As does obsessing over things beyond your control or ability to influence.
Try re-reading the newspaper, looking for articles you skipped the first time around.
Write emails you don’t need to write and edit them to eloquence.
Search online for your various ex’s until you discover that one, a biggie, has returned to her hometown where she works in the Budget & Finance department of the local university, serving as a “team member” on the Dean’s Office Feedback project.
If possible, locate her email address but do not find any recent photographs, however comprehensive your search.
Consider writing to her, and in fact begin several such emails, but then dig up your last letter to her, written four years previous and never sent, in which you relate the pathetic story of how your roommate at the time reported that she, your ex, had called saying that she was in town for just one day and was sad to have missed you, and how this moved you to tell her how much it meant to you to hear from her after five years of silence and how it made you realize what a jerk you had been to harbor bad feelings for so long, and how you had gone to bed that night filled with such happiness and relief, only to discover the following morning that the message had been left by another woman with the same name.
Remember the first time you and aforementioned ex had sex and how her then recent ex-boyfriend, who was also your boss, appeared at her door in the middle of everything, and how she went into the hall to talk to him while you stood naked on her bed, not knowing what else to do, and how you listened as they argued about the fact that he wanted to come into her room, only she wouldn’t let him – not for any reason, she said, but because he had no right – and how he kept saying that he knew someone was in there, because he wasn’t, as he kept saying, an idiot, and how you wondered if you should put on some clothes in case he decided to storm into the room, because you had a better chance in a fight with him with clothes on.
Contemplate new shelving strategies.
Put on the kind of music that befits the melancholic mood brought on by thinking about a woman who never loved you and who you never loved, as you would each periodically remind each other, and then discover, on further research, that she had placed 29th out of 37 entrants in the 34-39 age division of the 2001 Run for Independence 5K.
Calculate that as 10:36 a mile.
Repeat as necessary.