Yeow what are you using, a Brillo pad?

I'm joking!
I get frustrated when there's a pose in my head and I can't seem to jot it down in my sketch book, and I'm like, "Gah it's on the tip of my brain!" This is why I should buy a Deleter/Azone hobby doll, so I can use it as a pose dummy. It's got more articulation than standard wooden pose dummies, plus their bodies are shapely detailed.
I hate that too. Or you're trying to draw something... and you know whats wrong with it but you can't fix it right and it just frustrates me so much.