Or you learn how much progress has been made on the subject you're researching and, standing on the shoulders of giants, make new independent discoveries based on what has already been found.
It's not the Internet's fault if most people don't have the right mindset for research.
There are lots of people in the world smarter then you (and me). This might be humbling, but this can also be used to your advantage.
Instead of being sad about someone having had already invented what you thought about, build upon it! It's magic: you just thought about it, and it already exists, often ready to be used. Use it and build the next level. Pick the ready-made wheels, steel beams, a motor, and build something new, say, a car.
Sometimes, though it's the other way around. This has been done, but it still sucks so I'm going to do it better. Or sometimes, it's been done and works great for these people but not for me, so I'm going to make it better for my use case.
It goes both ways.
Be fair: the internet also gave us the first version.
What's frustrating is the complete lack of historical context to most things on the internet. There is one version: current, and everything previous is deprecated. Is this kid aware of every similar attempt to alter typography to save ink? Probably not. Should we throw him under the bus for being ignorant? Probably not.
What I see when I close my eyes is a community that assumes the OP might be right. That's all it takes, the presumption that this person, as young/Blubby/naive as they are, can find a better route up the mountain. I think it just takes patience &/ humility.
http://en.wikipedia.org/wiki/Monomyth http://en.wikipedia.org/wiki/The_Seven_Basic_Plots
I find that more and more often I think of something, then search on the internet, and if I see that someone somewhere has done anything similar, I abandon the project immediately. After all, it's been done, so what's the point?
Net result if we push this to an extreme: instead of pursuing interesting ideas people end up wasting time in useless discussions on Hacker News, thus adding exactly zero value and failing to move humanity forward.
At a first approximation, everything has been tried by someone. It is very, very rare to have a truly groundbreaking idea. But that's not a problem! Humanity advances mostly through incremental improvements, not just by giant leaps.
So stop criticizing and start doing.