I see this attitude a lot in the single, kid-free 20 something crowd. They can't understand why you can't just drop everything and go to the movies during the week. The kid-free 30 somethings, seem to have a better understanding of time constraints. I don't know if that's due to the fact that more and more of their friends have kids and they are just now used to it, their jobs are more stable and demanding, or they have just matured enough to not be so selfish.
I have a few friends that most of the time, I forget are only 23ish. Then they will say something and I go (to myself) "Oh, just you wait! Lets see what you have to say on this in 5-10 years".