There’s all kinds of reasons that you fall in love with one person rather than another: Timing is important. Proximity is important. Mystery is important. You fall in love with somebody who’s somewhat mysterious, in part because mystery elevates dopamine in the brain, probably pushes you over that threshold to fall in love.

Fisher frames romantic choice as a convergence of social circumstance and neurochemistry rather than pure fate. “Timing” and “proximity” point to opportunity structures—who is available and encountered when one is emotionally receptive. “Mystery,” by contrast, names a psychological trigger: partial uncertainty can heighten attention and reward-seeking, which she links to dopamine and the brain’s motivational circuitry. The quote suggests that love can be tipped into being by factors that intensify anticipation and novelty, implying that attraction is not only about a partner’s traits but also about the informational and emotional conditions under which we meet them.