If you're the kind of person who douses everything with Sriracha, you might just be a little masochistic. Let us explain: Capsaicin, the chemical in peppers, tricks your body's heat receptors into thinking your throat is on fire (it's the same reason alcohol burns going down). As this video from Vox shows, endorphins are released at the same time, so spicy food lovers turn the pain into a "burns so good" feeling.
And the idea that you'll get less sensitive to heat over time is a myth. It's just about teaching your body to associate the pain with the pleasure. Another myth: reaching for water to help stop the mouth-on-fire sensation. Milk, yogurt, rice, liquor, and even peanut butter help break down the oils in capsaicin, while water just spreads 'em around—making things even worse.