round the twist It's British & Australian informal idiom means :crazy Example: She's completely round the twist - just sits there all day talking to herself. I put the milk in the cupboard and the sugar in the fridge. I think I'm going round the twist.

"Round the twist" is an idiom meaning "crazy". "I thought I was going round the twist" means "I thought I was going crazy"

"Thought I was going around the twist" = I thought that I was going mad