Ringo Starr said that he wanted to open a hair salon after the Beatles dissolved (he didn’t think they’d last very long!).
Former NY Yankees center fielder Bernie Williams is a classically-trained guitarist who has a recording contract.
It’s a little known fact, however, that Mickey Mantle always aspired to be a Caribbean dictator, but nobody ever gave him a chance.
Dolph Lundgren has a master’s in Chemical Engineering and won a scholarship to (for? at? with?) MIT. Nice.
Sacha Baron Cohen studied in Cambridge and was considering pursuing a PhD before he became Borat. Not strictly relevant to the OP, but another interesting fact: his brother is a famous psychologist noted for his work with autism.
Hedy Lamarr’s now famous invention:
Kurt Russell was a Pro baseball player until he had a shoulder injury and fell back on acting instead.
Tom Cruise considered becoming a monk when he was a teenager. Other would be churchmen: Josef Stalin considered becoming a Russian Orthodox priest and Jackie Mason was a rabbi before becoming a comedian.
William Sanderson (character actor probably best known as Larry on Newhart or Farnum on Deadwood) has a law degree but started acting in college and ended up never practicing law.
Stephen Colbert intended to become a marine biologist but an ear injury as a teenager made it impossible for him to spend long periods of time underwater.
Johnny Depp moved to L.A. to become a musician and singer and took acting gigs (among others) to pay the bills. He never intended to become or studied to be an actor.
Danny Devito worked as a hairdresser and planned to remain one if his acting career didn’t work. He actually owns some shops that his sister (also a hairdresser) manages.
Samuel Clemens/Mark Twain probably would have spent his life as a riverboat pilot, which was his first love, had it not been for the Civil War. (He joined a Confederate regiment, found he didn’t really like getting shot at, deserted, and joined his brother in the Nevada territory where, there being no riverboats, he began writing for newspapers.)
Howard Zinn, now known as a historian and fervent anti-war activist, directly killed large numbers of people, probably hundreds, during World War II by dropping bombs on them. He was a bombardier aboard a B-17 Flying Fortress and he bombed numerous targets in Germany, Hungary and Czechoslovakia; he also dropped bombs on Royan, France, in one of the first ever military uses of napalm, which led to the fiery deaths of Germans and French civilians alike.
Oliver Stone is a decorated veteren of Vietnam. I think conscription in the last centiury was so universal, that we should not include military careers.
(British pop star) Robbie Williams is now a UFOlogist. 'Nuff said.
He’s also an airline pilot. A couple of times a year he flies a plane full of fans to a concert. I forget which airline he works for though.
One of his minor league teammates was Ron Shelton, the writer and director of “Bull Durham.” Shelton has said that Crash Davis was based on Russell, and that he’d wanted Russell to play the role. It didn’t workj out, so he had to settle for KEvin Costner.
Ulysses S. Grant hated Army life, though that’s the only career he was ever any good at. He really wanted to be a mathematics professor.
Cindy Crawford originally planned on being a chemical engineer but dropped out of college as her modeling career grew.
Ron Jeremy has a master’s degree in special education and worked as a teacher before becoming a porn actor.
Nigel Tufnel would have become a haberdasher or a surgeon.
Well that’s just stupid, she couldn’t play center field, you’d have to play her in left to hide her arm. She’d probably be a better bet than Felix Pie although she is 50 now.
Albert Einstein supposedly said something like “If I had it all to do over again, I would have been a plumber”.
Pamela Stephenson gave up her quite successful work as an actress to become a psychologist:
David Lee Roth is doing Paramedic work in New York.
I seriously came into this thread to say the same thing.
James Franco is really into painting. Singer/songwrtier Bryan Adams has been successful as a photographer and has a book or two of his photos published.