My 4 year old wants to be a wizard and a mommy. He'll have an easier time becoming a mommy if he achieves the wizard thing first!
My almost 7 yo wants to be a vet. She's said this-- and only this-- since she was 3, never wavering. She loves playing this Pet Pals game (psst-- I got it for under $10 PPD on e-bay). I can see it paying off . . .when we play vet, she asks really good questions. Tonight while we were at Picture People, there was a portrait of a dog up, and she was telling me how though it looked like a Collie, it was actually a Shetland Sheepdog . . .describing the differences between the 2 breeds. She loves looking at a dog breed book we have, always trying to pick the perfect breed. We don't even own a dog. (poor girl!) I hope she does become a vet because I would trust her completely with our animals!
My 3 yo used to want to be a firefighter. When she was in preschool for a few months, the firefighters did a demo involving Elmo, which completely freaked her out since she apparently does not like puppets like that. DD now refuses to look at/read/discuss ANYTHING about firefighters. On the notes home from the teacher, it said, "M asked Mrs. R to cancel the firefighters next time." It was shortly after the firefighter thing that DD protested going to school, so I pulled her out.