Some people are content to be couch potatoes. Others love the feel of using their bodies. I don't know if I exactly ENJOY digging post holes for corrals in caliche, but I don't mind it nearly as much as you would think, given what hard work it is. And I've been jogging for 40 years, because I enjoy the feel of getting out and using my body.
Many people prefer team sports, since they like working with other people.
Is it wrong to think some horses are the same? My 2 live in an L-shaped corral, with each wing running about 70 feet. When I get them out and let them run loose in a larger area, the mare bolts around in Arabian fashion, tail erect. Gallop, spin, gallop, spin, etc. The gelding likes to kick his heels as high as he can, a half dozen here, move, a half dozen there.
My mare seems happy to see me carrying a saddle. If I have empty hands, she notices but mostly ignores me. She prances a bit as we walk to the saddling area. Riding varies. I'm not a good rider, have a stiff back and often hinder her. Sometimes she is spastic too, in my defense. When we get it right, it feels great to me and she sure SEEMS happy. You can almost hear her say, "Look at me! I'm big, I'm strong, and I can MOVE!" At times like that, my main challenge is in moving roughly the same direction and speed as she is, and holding her back enough to prevent an explosion of action beyond my ability.
Our gelding was badly treated on a ranch in Colorado. We finally stopped riding him for 8 months, and then sent him to a local trainer for 5 weeks of 'breaking'. She knew him and knew he had been ridden a lot, but we wanted to reset him...so she pretended he was an unbroke horse. I went over 4 times each week to watch. Most of the work was from the ground. Once he was more confident, the mounted stuff went fast. He's been back for a month, and my daughter takes lessons on him (from the same trainer):
Does he ENJOY being ridden? Not entirely. But as he gains in trust, he seems happier. At the end, he'll join us as I ask how the ride went, and listens sociably while we discuss what happened. Maybe his more subordinate nature explains why he doesn't have the "Look at me! I can MOVE!" attitude of the mare, but his more sociable nature seems to take pleasure in being with humans, and if they want a ride...he's willing enough. I think he does understand a trade-off, with him giving a ride and receiving lots of positive attention.
He also seems to like work, so they may start learning some basic reining together. Right now, he's having a Sally Field moment ("...you like me, right now, you like me!").