If we’re new to a situation, or feeling unsure, we pay careful attention. We’re closely examining how others feel, what the cultural norms are, and what impact we’re seeking to make.
On the other hand, sometimes we fail to be on our best behavior. That’s another way of describing impulsive selfishness.
The surprising thing isn’t that being on our best behavior makes things go more smoothly. No, for many of us, the surprise is that it actually makes the experience better for us, not just the other folks.