I wanted, with all my heart, at various times, to become the foremost expert on Sertsi and prehistoric mounds and Stonehenge and non-Egyptian mummies and the Anastazi and the editor of The Smithsonian and Vogue, and find more complete, spectacular fossils than Lucy.
I am a bill collector, cattle rancher and cat herder, office manager and step-mom, shade tree mechanic, bookworm, and bookkeeper, cook, wife, friend, Auntie, and Doper.
Worked out for the best. 
I wanted to be a novelist. I’m now a stay-at-home-mom, so I have a little time to write after the kids are in bed.
In four years, when the baby goes off to kindergarten, I will have more time to write. The sequel will be finished by then, and I can start on a new series. Yeah, I’m doing what I wanted, just at a slightly slower pace.
When I was around 10 years old I became fascinated with electronics. I wanted to know how TVs and radios worked, dammit! I would spend hours and hours tearing apart old TVs and radios with soldering iron in hand. I would painstakingly unsolder every component and store it in a drawer cabinet. (30 years later, and I still have all those components.) When I was 12 I “worked” in a TV repair shop on Saturdays. I wasn’t experienced enough to actually repair TVs, so I just sorta hung out at the place.
Needless to say, I was interested in electrical engineering from a young age. And that’s what I am today.
I wanted to be a gypsy. I wanted dark hair, a long flowy skirt, a tambourine with ribbons, a wooden caravan and my very own horse to pull it. We would meander through the countryside singing and dancing and warm ourselves by fires made with sticks gathered from the woods…
I am a teacher/librarian.
But am a gypsy in my head!..
I wanted to be Han Solo, Indiana Jones, James Bond, and Slippery Jim DiGriz, with a side career of writing fictionizations of my own adventures, and doing some occasional consulting in high energy physics, but just as a hobby. Think Derek Flint, but without the self-aware characture.
Now I try to make rockets not fall over or come apart at high speed, maintain Linux clusters, and write e-mails to co-workers mocking abstruse corporate announcements and poking fun at dead-end programs. It’s not really my childhood dream–I don’t carry either a blaster or a whip, and people look at me funny if I wear my fedora–but I do have a fast car with a fancy navigation system, a personal communications device that lets me send encrypted messages almost anywhere in the world, and while I’m not as renowned as Joseph Heller or Mark Twain, I do frequently get to express myself in satire to the manifest enjoyment of coworkers and no small amount of accolades. The job isn’t especially thrilling, but it has its moments, especially when hanging off of a launch gantry in 50mph winds or watching a static test fire of a motor at 500 meters, and I get to see old ICBMs put to tasks other than lobbing nuclear weapons halfway around the world.
It could be worse.
Stranger
You work at JPL? Do you know Michael Werner?
Anyhow, my story is pretty much the same as SturmHauke. I grew up playing and loving video/computer games, but never really actively considered it as a career. But if you’d said to 12-year-old-me “hey, do you want to be a computer game programmer when you grow up?”, I would totally have said yes. Which is what I am now.
I wanted to be an actress.
I am now an insurance agent.
I will (hopefully) be starting law school next year and changing the course of my life, though I still won’t be an actress.
I wanted to be a writer.
I work part time as an e-retailer and my first novel is currently being assessed for publication.Weird thing, at 11 I had to write an essay on ‘What I want to be when I grow up.’ and I did this long spiel about how ‘Novelist’ was one of those goals that were unacceptable and rather than listen to people tell me how it was a silly goal - I told people I wanted to be a journalist instead. I’ve been a journalist. Later I said I wanted to be a scientist (made it to technician)
My brother, on the other hand, used to watch Sesame Street, and whenever the number painter guy came on (“Gonna paint a 6”) my brother would say “That’s what I’m going to do.”
He is a signwriter.
I wanted to be a scientist. I actually made it into grad school in computer science, but once I saw what a real career in research was like, I bailed with a masters.
Now I’m a game designer too. Twelve-year-old boys think I’m the height of cool.
I wanted to work with animals.
Now I work with actors, so I guess that is a yes.