My friend the bitch pulled the chair back a bit as I went to sit down. I didn't just stumble, I fell flat on my ass.
Same friend gave me a jelly leg and again fell flat on my butt.
I have a lot of similar stories, you get the gist. I fall down. Once I walked down a flight of stairs and as I hit one step my ankle sort of rolled, and then the next foot did the same thing on the next step and it happened pretty much the rest of the way down the stairs. Somebody actually asked me if I was drunk, stumbling down the stairs. And also, walking up the stairs another time, fell flat on my face.