One time I was doing a handstand on my own version of parallel bars. I could do it but couldn't keep my balance very long. One time as I tried to push myself out of a 90 degree arm bend, I lost all my strength. My arms were by my side and I fell square on my face. Needed stitches. Another time I punched a wall (it's a long story), mangled my hand, needed surgury and had a pin sticking out of my pinky knuckle for 5 weeks. It still occasionally aches to this day. Needless to say, that was enough to convince me to get my anger under control.