Capsaicin is a psychoactive substance
A local fried chicken restaurant calls their spiciest chicken WNFA (we're not fucking around), and it's exactly as it says on the tin.  When I have enough of it and I've gotten past the initial "why am I doing this? this is stupid, I should stop," I genuinely experience a form of euphoria. The next day is sheer hell though, so I don't do it often.  And that's how boring my life is, occasionally eating fried chicken to get mildly high.