There is a theory that testosterone makes physical exercise fun. No idea if it's true, or to what extent.

Anyway it's completely possible you just didn't find the right physical activity yet. It took me some years to realize that I have to exercise alone and outdoors.

Finding enjoyment in things that are difficult or painful is the probably highest impact quality of life lesson you can learn.

that sounds like masochism, or some kind of rationalization.

It depends on what you're doing. I could play sports for hours and completely lose my sense of time. If I had to run on a treadmill for 20 minutes I'd die of boredom.