Most of us have no idea what kind of partner will fulfill us long term.

Sometimes dating or married couples decide to split because things change—someone cheated or had to move—but, more often, people split up because things don’t change.

It’s common, for example, to enter a relationship unconsciously hoping that your partner will provide both an unlimited sense of stability and an unlimited sense of excitement—and then, when that’s not what transpires, to assume that the problem is your partner and that these qualities might coexist in someone else, whom you should therefore set of