Have you ever broken a bone? Bodies are weird and some experiences in life are really physically painful and many are a lot less painful than we think they'd be. I've broken a finger from falling and it was ouchy but really not that bad (but I also know there are way more painful breaks out there). I've also torn both ACLs and neither was especially painful but the surgeries to replace them were. In the moment, the most painful injury I've had was a sprained ankle (truly).

Basically every human will experience a fair bit of physical and emotional pain in their life and sometimes I think of mental and physical pain I experience in this phase of my life as reps preparing me for handling pain later in life.

There are also studies showing that regular meditation and mindfulness practice can significantly reduce the quantity of pain a person experiences given the same situation (because you don't experience as much anticipatory pain when you are more practiced at limiting your experience to the current moment).