I've eaten ghost peppers, hard candies made from extracts made from California reapers, and this crazy octopus sauce my sister once got at an Asian market where a single drop in a pot of rice bordered on painful for me... And one time I accidentally put in a splash

None of that bothers me on the way out - capsaicin just doesn't bother me at all once it hits me stomach. But other things do... Grapefruit for instance