That other guy, he's telling you the truth. I know it's crazy, but it's real.
Do you remember anything, before you got here? Like a tornado? It's not really a tornado, but it is a vortex, and it drops people off all the time.
Check your wallet. You'll have an ID that isn't yours, and that's the guy you replaced. I know it sounds insane, and it is insane, but insane or not, it's real.