Why is my wrist better after a painful pop?

I somehow injured my wrist last August (not entirely sure how; I didn’t notice anything specific but over the course of a couple days, it increasingly hurt to use my wrist or twist my forearm). The pain was on the top of the ulna bone right before my hand starts, and would be worse when I twisted my forearm or moved my hand sideways and outward. My doctor looked at it for 30 seconds and said it was tendonitis. Since then I’ve had good days and bad days. Braces didn’t seem to help, even wearing them for weeks, day and night, multiple times. Last night I was taking the trash out to our canisters and I was holding a bag while trying to open the lid, requiring me to twist my wrist in a weird way and I felt a strong POP (I did not hear anything), and that was followed by a deep, searing pain in the trouble spot that lasted for a few minutes. I didn’t think about it the rest of the night. The next day I thought about it again and expected my wrist to be sore, but it wasn’t. Not only was it NOT sore, but all the pain I’d had for months was just gone. Time will tell, I guess, but it’s more than half way through the day now and it still feels fine. What in the world happened?