If you’ve heard of John Green, it’s probably through one of two avenues: his work as an author or his hugely popular YouTube presence as one half of the Vlogbrothers. However, the scope of the John Green Internet phenomenon can be kind of hard to figure out. For example, what the heck is a Nerdfighter? Why do people keep Instagramming photos of their John Green books? And what’s up with the “Pizza” T-shirts? 

If these questions leave you flummoxed (or uncertain whether it’s really worth it to trawl through several hundred hours of YouTube vlogs), don’t worry: We have the answers. 

The Books

John Green’s books will make you cry. But, you know, in a good way. His best-known work is probably The Fault in Our Stars, currently being made into a movie starring Shailene Woodley. It’s a wistful Young Adult romance/coming-of-age novel about a teenage cancer patient and had a massive fan-following before it was even published. So massive, in fact, that when Green promised to sign every preordered copy of the first edition, he ended up signing 150,000 books. Here’s a video of him standing in front of all the boxes of those signed title pages, in case you don’t believe us: