So, stims. You've heard of them once, hopefully. They're when you sometimes flap your hands a lot because you're excited or happy. I have stims. Some people find them adorable while others find them annoying.
Why am I bringing them up? Simple. To say it's not just flapping your hands when excited. It's also clapping, jumping, or hitting things. Sometimes, my stims will be too much for me and I'll start hitting myself. It sucks. Not many people see though, for I am not excited often. :_)