Real vs. Perceived Size

Have you ever been surprised at your own size? I was at my son's back-to-school night the week before last, scoping out where to sit and subconsciously doing the "How fat am I in comparison to other people" mind-game... I picked a seat, next to a woman I'd identified mentally as a regular size-- certainly not fat. (This was all completely subconscious, mind you, I didn't know I was actually doing it until the next part happened...) I took my seat, glanced over at the the thighs of the woman in the seat next to me, and was shocked-- her thighs were about twice the size of mine. After pondering this for a split second, I thought: if this regular-sized woman is larger than me, is there a possibility that I am a regular size, too? How would I judge myself if were a stranger? It was a bit disconcerting, but in a nice way- a round-about way of seeing that I'm no longer obese, just large. How about you- has your own self-perception been challenged out of the blue like this?