It's a four-panel comic. Here's basically how it's structured:
First panel: Guy says something, often boastful, with friend listening
Second panel: Friend retorts somehow
Third panel: Guy realizes friend is right
Fourth panel: Guy is sitting down at desk with head in hands and wearing an expression of unpleasant surprise; the background is dark
How else can I describe it… The guy is white – not Caucasian, but literally white, your typical cartoon guy. He typically has no hair, ears, or nose. In different variations on it, though, he's often given other features to resemble someone. Y'know, he kind of looks like an older version of Fsjal. I dunno. I can't describe the meme any better than that.
I can't find any examples of it, but trust me, it's a real meme, notable enough not to be deadpooled. I'd be really surprised if this site didn't already have an entry for it; I just don't know what it's called.