Infants shown videos of snakes spend more time watching when the video is accompanied by a fearful voice than by a happy one. Fear is infectious, a virus mutating your DNA. Happiness floats; it doesn’t stay inside your marrow, multiplying with every blood cell. When you are afraid I’m afraid too; what do I do when the bravest person I know is flailing?

Sniffer dogs are likelier to signal false positives if their handlers believe drugs or explosives to be present. I just wanted you to be happy. I just wanted it to be okay.

Prairie dogs kiss more often if humans are watching. “Look how happy we are! See our linked hands, the brush of our noses against each other’s.” If we seem happy no one can judge us for everything we’re doing wrong. Chin up; shoulders straight; look capable.

The sexual arousal of men is dampened by sniffing the tears of a woman. I’m sorry for crying on your very best shirt while you were away; I planned to wash and iron it, fold it and put it away in your dresser like a sleeping baby. I didn’t mean to upset you. I swear I’m not unhappy.

The earth had become twice as dusty during the past century. Maybe that’s why I feel so old. Covered in dust, settling on everything that’s been left too long. I thought it was because of me that everything was wrong, but when I think about it without hating myself it seems possible that you just left me too long.

Apologies are disappointing. We both knew this a long time ago.