Paul McCartney turns 64 on Sunday.

He wrote the song as a goof on his dad shortly after the elder McCartney had reached the age his son will be day after tomorrow.

Paul's mother had died of breast cancer five years earlier, as did his wife Linda seven years ago.

... About 2.7 million other Americans observe their 64th birthdays in 2006, including Muhammad Ali, Erica Jong, Larry Flynt, Garrison Keillor, Michael Bloomberg, Harrison Ford, Ted Kaczynski and Barbra Streisand. (Ringo Starr, the only other surviving member of the Fab Four, will be 66 next month; John Lennon was murdered at 40 in 1980; George Harrison died of cancer at 58 in 2001.)

"The slogan back then was 'Never trust anyone over 30,' " recalled Jeff Greenfield, the CNN commentator, who is 63. "We thought people would be dead or in a home by their 60's."

Today, on average, 64-year-olds can expect to live more than 16 years, about 4 years longer than 64-year-olds could expect in 1967, according to government statisticians (and, hey, an editor of the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report, Jude Rutledge, was named for another of Mr. McCartney's songs).

Here's hoping my favorite Beatle exceeds the life expectancy.