Yeah! It took me a long time to learn that. As a young gay man, I wasn't really all that into anal sex anyway, and when I was into it, I was a top.
That wasn't because of any innate sort of characteristic about my psyche. It was because when I was 18, I had a terribly painful experience trying to bottom! And then I had another painful experience a couple years later, so I just figured I wasn't built for it.
But it turns out that what I wasn't built for was inexperienced topping partners and a lack of personal knowledge about how to bottom without pain.
Pushing out makes a really big difference, and it's not something I ever would have just figured out on my own. I had to read about it! I had to read that pushing out opens the outer sphincter, allowing the inserting process to begin relatively painlessly.
You still have to get past the inner spincter, over which you don't have any conscious control, but by pushing out you reduce the problem to one problem instead of two at the same time.
A big help!
I never did learn to be an enthusiastic or frequent bottom, but I did learn enough to make bottoming an occasionally enriching part of a sexual relationship. When it's good, it's very good!
But it doesn't come automatically.