I think you're humanizing or overestimating snakes' brains a bit much here. It sounds as though you're very concerned for the snake's mental health?

What you should realize first and foremost is that snakes are not like dogs and cats. They don't have the mental capacity for "pleasure" or other such emotions. They are much more basic. They know to be scared, and have the basic fight or flight instinct, but it doesn't go much farther than that.

When it comes to socializing and "taming" ball pythons, you're just looking to condition the snake to accept handling as a safe event, not triggering flight or fight in them. You aren't going to scar the snake or "make him feel bad", he's not that mentally evolved. You may scare him a couple times, but that's just part of reptile keeping and indeed, animal keeping in general.

Follow the advice others gave you, and with time and patience you should have a nice, calm ball python. Just don't stress to much about traumatizing it