Presidents George H.W. and George W. Bush

No matter what your political views, you've got to hand it to the two President Bushes for being just the second father-son U.S. president combo ever, after only John Adams and John Quincy Adams.

Like-father-like-son political ambition runs in the family: The elder Bush's father was U.S. Sen. Prescott Bush and the younger Bush's brother, Jeb, served as Florida governor.

Growing up in his father's shadow must have been intimidating for Bush Jr. After all, the elder Bush was once the U.S. Navy's youngest aviator, became an oil millionaire by age 40 and was a congressman, U.N. ambassador, CIA director and vice president before becoming president.

And you thought living up to your dad's accomplishments was a tall order.

If the elder Bush is any indication, his son can expect a long and healthy life. Bush Sr. celebrated both his 75th and 85th birthdays by skydiving. We wouldn't put it past him to do so at age 95 either.