Used to think it was a boast when people said that they weren't capable of sleeping late

But it's not. It's so not a boast. It's a complaint.

I stayed up a bit late on Sunday night, intending to make up for it by sleeping two hours later on Monday morning (at 7 AM instead of 9 AM). But I woke up at 7 AM anyway, and I immediately knew that there was no going back to sleep. God, it was the worst.