So I am a Nerdfighter. Not a very active one, but one nonetheless, as an ardent fan of both Hank and John Green and their works. I believe in what they do, I believe they have the right idea, and I think the more people get on board, the better.
But I'm not here to talk to you about being a Nerdfighter. ("Do you accept the Greens as your lords and saviours?" I can think of few worse candidates for door-to-door religion than me.) I'm not even here to talk about both of them - sorry, Hank. Nor am I here to talk about John Green as a person: I'm here to talk to you about John Green's writing.
His books are listed as Young Adult, which I think is good, because if I had learned the lessons his books have taught me when I was a Young Adult, then I might have ended up being a better person.
Only one of the man's books have lasted me more than two days, and that one is co-authored - that isn't the reason why, though. David Levithan's contribution to Will Grayson, Will Grayson was hugely affecting in its own way. It was a harder read, because it dealt with several things that I have quite intimate experience of - but then, so do the rest of the books. Just not in the same direct way.
The man is just so good at people. How we're all different, and weird, and how we're also very much the same. How when it comes down to it, we don't need to have a lot in common just to get along with one another. How, sometimes, we're our own worst enemies - and sometimes we don't have enemies. Sometimes things just happen and we are left to try and make sense of them.
Almost everyone will deal with terminal or serious illness in their lives - either affecting them or someone close to them. So at first, The Fault In Our Stars seems to trivialise something so very important; but this impression doen't last long, because that's the point. It take away the immediate thoughtless solemnity and replaces it with actual applied understanding of what it means to be a grenade, primed to hurt those you love the most - or how hard it is to convince the grenade that you can bear the shrapnel, for their sake.
Almost everyone will also be affected by a simple feeling of not mattering - of wanting to matter, and finding that we don't, to our own specifications. Of wanting to set our own terms, of setting a bar that we have to cross to be in the realm of People Who Matter, and then doing just that. We all know life doesn't work that way - but An Abundance Of Katherines teaches us why, and then teaches us that it's okay, because that isn't what mattering means anyway.
And this is why I think, if one wants to be a better person, and understand persons better - that they should pick up at least one (or preferably more) John Green book. You may end up with tears of some form or another staining the pages. It will be worth it. If you aren't touched, moved, or galvanised into some form of feeling or understanding - hell, just give it to someone else...
(I'm not telling you why Will Grayson, Will Grayson hits close to home, by the way. One part of it should be obvious from the blurb, another is a big plot twist that I won't reveal.)
So go and read this man's work. If you do nothing else - at least give it a shot.