Exactly.
But it's a bit more introspective than that. It's the point where overconfidence in one's abilities, that past performance is indicative of future results, the attitude of: oh sure, I can do that, no problem conspire to give on an overstated opinion of one's self.
An AT told me a long time ago it can take weeks to build up a level of fitness and only days to loose it. I didn't disbelieve it, but a lot of things don't become real until one experiences them first hand.
No it doesn't
really suck. It sucks to have to admit that I'm not as good as I think I am.