20 is an ok age. Really, what you lose as you get older is time, commitment, and desire. You will understand when you are like 28-33. You probably think right now, there is no way you would ever lose the drive. But you will. Real life starts having demands. Jobs/school/family/women/desire for kids, house, stability, you name it. Not to mention, league may not even be around in 5-6 years in its current popularity. IT may be a diff. game. I'm 33.5 years old. Ive played online games since I was 15. I still play way too many games at my age. But, I couldn't be pro or even as good as I was back in the day. I tore some FPS games up back in the day. I played in tournaments, I lived and breathed games. But, times change. I honestly cant even stay interested in FPS games anymore. Adapting to change is a big part of it, too. You just learn slower, if that makes sense. You react better, though, when you learn it. Its a weird conundrum.
Really, if you want to make it a dream, you need to not be looking for season 7 or 8 or whatever. You need to start plowing games RIGHT NOW. Thats looking too far into the future in what I consider a volatile market. I mean even if you make challenger, its like 25 total NA players nowadays in LCS. You are trying to squeeze into that 25-50 player range. Personally, I would look more towards streaming, and plow games and hope to get pro, and if not, build up a streaming personality and make money that way while you finish college.
Thats my one regret, at 33.5 years of age. I dicked around, due to partying, and gaming (I was hooked on gaming during my early teens/late 20s), and I flunked out of college and didn't go back until I was 29 years old. I got my Bachelor's last December, at 32 years old. If I had it to do all over again, I would have knocked that shit out by 22-23 years old, and then gamed/lived my ass off. I had fun during my early 20s, but I'm paying for it now.