I wanted to be a firefighter when I was really young, but eventually I grew out of that dream, and looking at it now I certainly know I don't want to be one.
Then came race car driver because of GT2. I didn't care whether it was F1, WRC, NASCAR, I just wanted to be a race car driver. I really wanted to find a racing series with R34 Skylines with "stage 3 weight reduction". Part of this was because my dad and my uncle used to drive race cars (Chevy Nova's) when they were younger and it seemed really cool.
If I remember correctly, I think there was a little while when I wanted to be a Pokemon master, never really chased that dream
Then came NHL player, which I wanted to be until I turned 13/14 and realized it would never ever happen

(incidentally, this is also when I began to love the sport).
Then I thought I wanted to be a cop, but after a while I realized it just isn't what I wanted to do; I'm sure I'd be a good cop, but I don't think I'd enjoy it. That lead into wanting to be a soldier, but I changed my mind on that one after seeing how many Canadian soldiers died in Afghanistan (as well as how woefully under equipped and under funded the Canadian military is).
After that, I wanted to be a fighter pilot, but unfortunately I'm colourblind (I would...maybe be able to pass the eye test, but I'm also lazy which rules out the Air Force unless I want to fly a desk).
Then for a while when I was 14/15 I wanted to be a lawyer because I'm argumentative

. I looked into the cost of law school and the realities of being a lawyer, which changed my mind on that path.
Finally, at the moment my career aspiration is accounting (hello ladies

). I don't necessarily want to be an accountant for the sake of being an accountant, but I see it as a bit of a means to an end. I'd like to get into business, and I'm taking a business degree at the moment (first year), and I think a BBA or BComm on its own is a bit of a fluff degree. I'm interested in accounting so I can get an accounting designation (likely CMA (Certified Management Accountant)). I see it as a way to get something more tangible and prestigious out of a business degree (inb4 MBA).
The original desire was to be a CA, but I think I'd prefer the CMA designation. I've looked into both, and the CMA designation seems to be more up my alley as far as career paths go. The CA accreditation process is long and grueling hours, and I don't want to spend my 20's working 60 hours a week at a big 4 firm in Toronto.
So that's my career aspiration at the moment, it's very much subject to change. I don't have to declare a major until the end of my second year, and by then I'll have been able to get a bit of a taste of most aspects of a business.