In high school, I had this teacher that I really looked up to, a hero. He taught history, made it really interesting and exciting. He was an ex army coloniel. He looked and acted like he had stepped right out of a movie. He exuded charisma. He told all of these stories of incredible things he'd done and seen. A truly larger than life personality. The students all hung on his every word. I was impressionable, I thought of the man as a mentor, and in my eyes he could do no wrong. All I wanted to do was impress this man.
When I was about to graduate high school I was in his office, he asked me what my plans were. I was a techie, geeky kid and I'd been programming computers since I was 9 and had a dream of having a job at NASA. I told him I wanted to work there. He laughed, and it wasn't really a nice laugh. It was a "you're being a fool" kind of laugh. He said "Eddie, you need to be more realistic, set your sights lower. My sons are top of their class at Virginia Tech, and even *THEY* probably won't be able to get a job at NASA. You need to spend a little less time with your head in the clouds." As you can imagine this was devastating.
One of my personality traits is stubbornness, if someone tells me I can't do something, I will cross oceans to prove them wrong. I don't even like it when it happens to other people. When Simon Cowel tells some singer that they are the "worst singer in the world" and they'll never "be a good singer" I want them to go on to be one of the biggest, most successful vocalists in the world and come back and make Cowel eat his words. Making a blanket statement about someone in the present is kind of a moronic thing to do, there's no telling what that person might accompish.
Before I even finished college, I was working part time at NASA, and my first full time job after graduating was at NASA, working as a systems analyst on the Earth Observation System project. I didn't do it to prove "Mr. Smith" wrong, I did it because it was a dream of mine.
Years later I did think about going back and slapping my NASA badge down on Mr. X's desk. Giving him a piece of my mind - that he should be trying to encourage kids, not crap on their dreams like an idiot. That by doing so, not only was he not worthy of being my hero, but by crushing kids dreams he was a pretty shitty teacher. I didn't.
I guess the take home here is, heroes are important, but they're human just like everyone else. In the end, you should not determine your self worth based on what someone else says, no matter how great they seem.