Ages ago, I think perhaps when we bought our house 8 years ago, my grandmother gave me a Christmas cactus. It sat in the big window in the den and the evil kitty Tac chewed on it. The cactus had dozens of small little teeth marks in nearly all of the leaves/spines/branches/whatever they’re called. I moved the cactus to another window and it slowly healed. Never has it bloomed. I figured that the cactus was so traumatized that it would never bloom.
This summer it spent a lot of time outside getting rained on and I guess the outdoor treatment was just what it needed because it has bloomed and from the looks of it there are lots of blooms to come.