Your experience is not universal or even typical. I have never seen anything like this in the thousands of times I've eaten spicy foods with hundreds of family members, friends, and business associates. I have literally never seen someone insist that they can handle spicy food, and then start behaving like a child. In my experience, they try to hide it because they are embarrassed they can't handle it.

The only thing that even came close was someone who was challenged to do a shot of Carolina Reaper sauce and he started hiccuping then had to excuse himself to go to the bathroom.