Jennifer Taitz, a clinical psychologist, opens with one of the most researched and most consistently ignored findings in relationship science: the belief that a partner is the source of happiness — what she calls the 'husband treadmill' or 'partner treadmill' — reliably reduces both the quality of relationships you form and your baseline wellbeing while single. Here is why: when your emotional baseline is built on the expectation of partnership, singleness feels like deficit. You are not building a life; you are waiting for your life to start. And when a relationship does begin, the expectation that it will fix the deficit is so high that the reality almost always disappoints. The people who have the best relationships are almost always the ones who were building a genuinely full life before the relationship arrived — not people who waited.