Most of the important things here have been said, so I’ll chime in with some thoughts of my own.
Back when I was 17, I had no fucking idea what I wanted to do. I spent most of my time playing video games, and imagined I would be working in something related to programming or video games, because those things were the only things that interested me at the time.
Then, I found out what I wanted to study at the age of 18, purely by accident. It wasn’t a field that was even remotely on my radar before I stumbled over it, but long story short: I’m now delivering my master thesis in molecular biology this October.
And, also interestingly, I’ve also discovered several other fields I now think seem really cool, but thought seemed like a total waste of time back when I was a teenager. I thought mathematics, physics and finance all were really boring six years ago, but now these things actually seem interesting.
The point here? My perspective of what I think is interesting has changed completely over just a few years, and the same thing is probably going to happen to you. You’re a teenager. You’re practically still a kid. Things will change.
As for the fighting game-thing? I started playing SF a month or two before I made an account on SRK, and has spent a lot of time on them. I can honestly say I didn’t understand squat about fighting games before about 10 months ago. I thought I did, but I really didn’t. Yet I’ve already gotten better than I thought I’d ever be when I started playing, I’m still learning new things whenever I play, and I still know that I have practically no chance of making a living out of this. Nor would I want to. I love playing fighting games on my spare time, I’ve met a lot of cool people in the FGC, but making a job out of this would ruin everything.
My two cents on this.
edit: also, one last point: last year, I went to a CPT-event where Luffy was attending. This was in the post-EVO months where he was on a hot streak and won absolutely everything he entered, and made good money while grinding Pro Points for the CPT. One of my friends talked to him a bit, and at one point during the conversation he asked him “So do you still enjoy playing SF4?”
His answer was a straight-up “No”.