Yeah, maybe when you're 16~18, then you grow up and understand just how hard it is to make a difference even in your own social circle, let alone the world. I guess people should stop pretending all the great man and woman we hear about today did their thing alone. They all needed someone else, even if just to make their ideas popular or to give them financial means.

I've never claimed I envisioned doing it solo. That's where most of the disappointment actually came from: teaching assistants and professors were so uninterested in the subjects they were giving, they'd hardly motivate anyone, let alone give them a chance to participate in anything world-changing. Even to the point that out-of-the-box creativity was punished. That drove the student body to turn into an exam-passing automata.

Universities are a perfect place for that, and I hoped for such a stimulating environment. I did end up meeting a teacher or two in later years that met my expectations, but they never stuck around long enough.

And no, the fame is not the driver, imho: I believe all humans would gladly contribute to a challenging problem solution, without requiring ego satisfaction (that can come later :)).

One of my favorite lessons in making a difference:

https://www.youtube.com/watch?v=fW8amMCVAJQ

Of course they do. Do you think everyone who plays sport believes that their sport can somehow transform the world? Do you seriously think every bassoon player and salsa dancer believes they're going to change history?