most of my embarrassment comes from falling down. i still remember when i was 12, i was going to meet my friend after school (i was homeschooled) and i was walking and bouncing a little rubber ball. there were a ton of kids around, but i saw my friend and started walking faster towards her before i bounced my ball, stepped on it, slipped and fell flat on my back in front of a massive group of kids.
another classic was this winter when i slipped on some ice in front of a group of three girls and i landed on my back and then laughed and said ‘just leave me here’. none of them laughed, and they just looked at me with weird expressions and kept walking.