When the thing has become a Tumblr meme, it's officially over. The thing in this case is the fedora, and the meme is a Tumblr blog called Fedoras of OKC [OK Cupid] and the related Fedoras: Forever Alone.
The fedora was once associated with authentically cool, tough guys. Think: Frank Sinatra. Think: Bogart.
Then a funny thing happened: the fedora (or the even worse trilby) became popular all over. The skinny 23 year-old guy working at the Starbuck's wears a fedora outside of work. Pale men with questionable facial hair standing outside of clubs: fedoras. Your 16 year-old nephew, who you were diapering only a few years ago (it seems): yep, fedora.
Boing Boing points out that the modern fedora movement made its rounds through the "bro culture." Then fedoras migrated into the world of geekdom, and it was all over.
What do you need to wear a fedora and pull it off? Things that most of us do not have:
A well-cut suit; angular face; and the hardest of all to achieve, the ability to go back in time to 1947.
So, lose the fedora. Fedora culture: officially over.