1. As a teenager, Bush contracted a serious staph infection and nearly died. Once he was well, he repeated a year of high school to make up for the lost time.
2. As a senior at Phillips Academy he wanted to enlist in the military after the Japanese attack on Pearl Harbor in 1941, even though he had been accepted at Yale. Despite his father's disapproval, he signed up for the Navy's flight training program on his 18th birthday.
3. When he received his Navy pilot's wings, he was the Navy's youngest pilot.
4. In early letters, he called future wife Barbara "Bobsie." Recounting his decades of letter-writing in his book "All The Best," he said he doesn't remember calling her that.
5. The 20-year-old Bush was shot down in a raid on the Japanese-held island of Chichi Jima in the Pacific in September 1944. Despite being hit by anti-aircraft fire, he continued toward his target and scored several hits before bailing out. As Japanese boats were fast approaching,he recounted in his book: "I was crying, throwing up and swimming like hell. I could have made the Olympics that day because we had to get out of there."
6. Back on temporary duty stateside with the Navy, he received orders to ship back to the South Pacific to participate in the invasion of Japan -- but Japan surrendered before he had to ship out.
7. When he was leaving the military he seriously considered not going to college but instead getting a job. He writes in his book, "My father definitely did not agree with my plan of not going to college." He eventually enrolled at Yale.
8. His nickname since childhood had been Poppy, and that's how he was known at Yale -- especially as a baseball player. He signed early letters "Pop."
9. Bush played first base at Yale and was team captain. He played in two College World Series and had a career batting average of .251.
10. He met Babe Ruth in 1948 shortly before Ruth died. He accepted an autographed copy of "The Babe Ruth Story" when Ruth visited Yale.
11. He finished Yale in 2½ years and graduated with a degree in economics, already married and the father of a son: George W.
12. Bush debated what to do after graduating. He had offers from an oil and gas firm in Texas and an investment company in St. Louis, but also considered teaching. He went with the oil and gas option.
"I started at the very bottom of the corporate ladder as an equipment clerk," he recounted in his book. He later started his own oil firm.
13. The Bushes' first home in Texas was a house with one bathroom which they had to share with their neighbors, "a woman and her daughter, both of whom seemed to make their living by questionable means.
"Let's just say they had a lot of male visitors at all hours of the day and mostly night. Many a night they locked us out of the bathroom," he wrote in his book.
14. According to the book "The Presidents Club," former President Dwight Eisenhower urged Richard Nixon to consider Bush, who had won a congressional seat in 1966, as his 1968 running mate. Billy Graham, who was close to the Bush family, also had raised the possibility with Nixon.
15. On August 6, 1974, Nixon called a Cabinet meeting which Bush, then chairman of the Republican National Committee, attended. He was sitting against the wall and tried to get the President's attention. Finally, he was able to speak and he said that Watergate was sapping the public's support and urged the President to resign. Nixon did resign, three days later.
16. After serving as envoy to China, Bush wanted to return to the U.S. and asked for a Cabinet position. Instead, President Gerald Ford offered him the job of director of the CIA, which he took. Bush served from January 30, 1976, until January 20, 1977, heading the agency during a time when it was under attack for some of its activities. On July 5, 1976, he gave presidential candidate Jimmy Carter his first daily intelligence briefing after Carter asked for them. Bush is the only head of the CIA to become president.
17. How loyal is he? In 1980, while Bush was running for the Republican presidential nomination, his campaign ran low on money and many of the staff volunteered to work at half their pay. After he pulled out of the race, Bush wrote notes to the staff with funny sayings, thanking them and including checks for the half pay they didn't get in the last two months of the campaign.
18. When Ronald Reagan was shot, aides wanted then-Vice President Bush to chopper back to the White House but he refused, saying only the President lands on the South Lawn of the White House -- so he flew to the vice president's residence instead.
19. Bush was the first sitting vice president to be elected president since Martin van Buren in 1836.
20. When he became president, Bush offered his predecessors -- Nixon, Ford, Carter and Reagan -- secure telephones so he could reach them day or night. According to "The Presidents Club," this wasn't just a kind offer; Bush knew he had a better chance of gaining support for his decisions if he confided in the former presidents and asked for their advice.
21. Bush came up with a unique staff award, the Scowcroft Award, which he described as a "highly coveted recognition" given to Cabinet secretaries and White House staff -- but not for exemplary work. As he described it in his book, the award went to the person "who could fall asleep in a meeting but make a good recovery and act as if he or she had not been sleeping." It was named in honor of Brent Scowcroft, his national security adviser, who Bush said worked impossible hours.
22. In the aftermath of the 1991 invasion of Iraq, Bush's approval rating hit 89% -- the highest for any president at that time. By the next July it had fallen to 29%.
23. It is common knowledge that Bush does not like broccoli, but how far did it go? In 1990 he banned it from his plate whether he was in the White House or on Air Force One.
24. One of his favorite snacks was pork rinds. In fact, he was named "skin man of the year" by some in the industry.
25. He had a dog biscuit dispenser in the shape of a gumball machine in his office at Camp David. He tried unsuccessfully to train his dog Millie to tap a lever to dispense her own biscuits.
26. While he may be best known for his foreign policy achievements as president -- overseeing the response to the fall of the Berlin Wall, the 1991 Iraq war -- his domestic accomplishments are also noteworthy. In 1990 he signed the Americans with Disabilities Act and the Clean Air Act -- two key pieces of legislation that still have an impact on the country.
27. One of the Democrats he got along with best was House Ways and Means Chairman Dan Rostenkowski. Although they disagreed on policy matters, Bush called "Rosty" one of his favorites and hosted him in the White House. "I do not want the battle up there to affect a friendship that means a lot to me," Bush wrote to him in one letter. According to Bush's book, Rostenkowski's later legal problems -- which eventually sent him to jail after allegations involving the House Post Office -- did not sour Bush. He called Rostenkowski in jail and stayed in touch.
28. One of the most embarrassing incidents during Bush's presidency -- when he threw up during a 1992 dinner with the Japanese prime minister -- happened because Bush ignored his doctor. Bush told his doctor earlier that night that he wasn't feeling well and his doctor suggested that he skip the event. Bush didn't listen.
29. After a bitter 1992 campaign, Bush left a handwritten note to his successor, Bill Clinton, on Inauguraton Day: "I wish you great happiness here. I never felt the loneliness some Presidents have described. There will be very rough times, made ever more difficult by criticism you may not think is fair. I'm not a very good one to give advice; but just don't let the critics discourage you or push you off course. You will be our President when you read this note. I wish you well."
30. He reached out to then-Vice President Al Gore on the night of December 16, 2000, after Gore conceded the contested presidential election to his son, George W. Bush. Bush 41 was impressed with Gore's concession speech and called the White House and asked to be connected to Gore, and they had a brief conversation.
31. Golf Digest ranks Bush fifth among presidential golfers, and he has a reputation for playing fast. "You put your track shoes on when you're playing with him," professional golfer Hale Irwin told the World Golf Hall of Fame, into which Bush was inducted in 2011.
32. Bush boosted the sales of horseshoes after he installed horseshoe pits at the White House and Camp David. He had horseshoe tournaments at the White House which included teams from the household staff, the medical unit, the Secret Service, groundskeepers, Marine One and Air Force One staffs, and his team -- himself and his son Marvin.
33. Former Sen. Alan Simpson, a longtime friend and frequent hunting partner, describes Bush as a "crack shot." About eight years ago, when Bush began to have a hard time walking, he told Simpson and others in their hunting party, "Boys, you scare them up" while he took aim from the truck. He fired at two targets from the top of the truck, Simpson recalled, and hit both.
34. He became a convert to e-mail pretty early. In 1999 he wrote a letter to friend and columnist Hugh Sidey, saying, "Twelve months ago I was a Fax man or a phone man. Now I e-mail everyone in the office and tons of people outside the office. I am hooked," he wrote. "I can use color and differentiate fonts to emphasize things and I can forward Monica Lewinsky jokes."
35. Bush tagged himself "41." In "All the Best," he talks about how after George W. was inaugurated, people would ask what to call the elder Bush now that there were two President Bushes in the family. "I like #41," he said.
36. He was not happy with a lot of the criticism his son George W. got as president. In "The Presidents Club," Laura Bush tells her father-in-law to stop watching TV news. He also would read criticism on the Web and draft responses to columnists and pundits, but he would delete them before hitting "send." He told the authors, "Watching your son taking a pounding from his critics was much, much harder" than taking the hits himself as president.
37. He has stayed in touch with a very diverse group of people. Some who have visited him in recent years in Maine include baseball star Roger Clemens, tennis pro Chris Evert and the country music group The Oak Ridge Boys. He also stays in contact with members of the White House personal staff he knew while he was president, including some of the butlers.
38. Pop star Taylor Swift is now good friends with the former president. Swift met Bush when she was in Kennebunkport to tape a television show and Bush brought some of his grandchildren to watch.
39. He is a huge writer of letters and cards to family, friends and colleagues -- often showing a softer side than what was seen in public. One revealing letter to his children is dated July 23, 1974, a couple of weeks before Richard Nixon would resign over the Watergate scandal. He offered an analysis of Nixon and his mindset: "I shall stop with this gratuitous advice. Listen to your conscience. Don't be afraid not to join the mob if you feel inside it's wrong. Don't confuse being 'soft' with seeing the other guy's point of view." Or this letter from "The Presidents Club" to George W. at the onset of the Iraq War: "You are doing the right thing. Your decision just made is the toughest decision you have had to make up until now. But you made it with strength and compassion."
40. Throughout his political career Bush kept 3-by-5 cards with the names and contact information for thousands of political contacts he would stay in touch with through letters, calls and notes.
41. Bush has parachuted eight times: Besides being shot down in 1944, the other seven were voluntary, including jumps to celebrate his 75th, 80th and 85th and now his 90th birthdays.
By Kevin Bohn
CNN's political research director Robert Yoon contributed to this story. Sources: "All the Best"; "The Presidents Club"; www.Senate.gov; "The Pawprints of History: Dogs and the Course of Human Events"; "Inside the Presidency of George H.W. Bush"; "George H.W. Bush: The American Presidents"
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