Hair that always hangs neatly in place (like perfect bobs) without the kind of intervention mine needs to even look half decent.
Bit weird but the more mobility issues I have I sometimes just notice people walking, or maybe more running, about and it seems strange it looks so easy and natural with no real effort required.
I envy people who can draw but with that special something that just makes it stand out, like when pencil drawing a portrait and the likeness is just amazing to see.