If it "ruined" your growth, it's only because you didn't try. As a wise man once said: it's better to have tried and failed than to have just failed.
Most of my public school education was a complete waste of time, but I didn't expect those people to help me. I learned computers on my own, read countless books on all sorts of topics on my own. Libraries, even sucky ones, are filled with tons of stuff you don't know.
I never asked for permission or for people to give me opportunities to try different things, I just did things that interested me. My programming teacher in high school talked to a local business owner and recommended me for a database programming job when I was 15. That was the first time I realized people would pay me to do stuff I enjoyed doing on my own time. None of that came from what the school gave me, but what I did on my own.
The only one who will ever help you is you. If that guy gave up on you, you're doomed.
And for those who are doomed: when I order something with onion rings and a shake, I don't need to be asked if I'd like fries and a drink with that.