The same thing kind of happened to me today. A couple of months ago I was paddling to a campsite and got my thumb slammed in between my canoe and paddle. It swelled horribly and I thought I had broken it. It turns out that it was just a severe contusion on the actual thumb joint. It is still a little sore these days, but I am getting better.
Anyway, I used to do this thumb-pop thing that looks as if I'm double-jointed. It turns out that my little trick, which I've always been able to do on both thumbs, is not a double-joint thing, but a weak tendon instead that allows the ball in my joint to move farther out than most people's thumbs move. In other words, the doctor said my little trick was abnormal to most people, and it is often seen after surgery and that symptom often means the person's thumb is useless to them without some sort of therapy. I have apparently learned to live with this abnormality, and have grown to rather enjoy it.
Well, since my injury, I haven't been able to "pop" my thumb, and this has concerned me. After all, I've been doing this all my life. When I asked the doc about this, he smirked and basically said, that injury of yours actually made you normal in the end. So I guess me being born was me falling into a well, and my canoe incident is me being kicked in the head by a mule. It's a funny world.
PS - I apparently can stretch the scar tissue that is keeping my thumb from "popping" until it allows me to "pop" it again. The doc wasn't sure why I would want to do that, but I liken it to putting one's toes in a pair of super-tight climbing shoes for hours on end. There comes a point when one wants to wiggle the toes just because one is used to doing so. However, when one can't wiggle as a result of the tightness in the shoe, one can, conceivably, become irritated. I am officially irritated.