> Everyone that talks about the good feeling you get afterwards either has different physiology, feels pain to a lower degree, or just has a better willpower + long term view.

My experience is that I don't feel good after exercise at first. I have to keep it up for multiple weeks, until my body actually gets fit enough that I can pass some inner threshold of a Real Workout, and get my reward of a happy kind of exhaustion.

I'm currently out of shape and fighting to try and get myself to go exercise regularly enough that this happens again. It's not easy.