Actually, I knew. We were immature and playing for longer than other kids but there was a feeling the last time. I can picture it now, running around in the dark giggling and as our Make Believe characters. It was harder to assume our roles that time. We promised to play again at the next sleepover but somehow, I knew. There was a crisp winter feeling of finality and I felt that we were leaving the world of pretend behind. The next time we hung out we did other things that were fun. Dance to Whitney Houston, read books, sneak into their mom's room to try on all of her random hats, general pre-teen shenanigans.
I think we knew we were behind. At least I was aware of it. For a while we didn't care but the horrors of puberty come for us all I suppose.