Self-control is important.

There's a belief that being in a relationship entails that you be yourself, fully, at all times.

Well, in reality, when you love someone and you want what you have to last, you might need to learn how to caution some of the ways you feel and act.

It general, this will prevent you from making split-second-feeling-based decisions that would have been overlooked if it was given logical reasoning, giving rise to regrets and unnecessary apologies.