I do wear one of those fancy FitBits, though, which means I at least have some sort of aspiration to exercise. I go to the park across the street a couple times a week to "get my steps in". There I see young people and old people and couples and dogs and even kids jogging along looking all glowy with the sweat of a fit person, and I think to myself, "It must be nice to be so strong and awesome like that." I get uber jealous of runners sometimes.
Some humans are dissatisfied with their bodies. They pick, poke, and prod areas of their bodies that they deem to be lesser than others areas or lesser compared to an area or body part of another humans. They wish to have attributes of some other human.