People love pretty much the same things best. A writer looking for subjects inquires not after what he loves best, but after what he alone loves at all. Strange seizures beset us.
Why do you never find anything written about the idiosyncratic thought you advert to, about your fascination with something no one else understands? Because it is up to you. There is something you find interesting, for a reason hard to explain. It is hard to explain because you have never read it on any page; there you begin. You were made and set here to give voice to this, your own astonishment.
Write as if you were dying. At the same time, assume you write for an audience consisting solely of terminal patients. That is, after all, the case. What would you begin writing if you knew you would die soon? What could you say to a dying person that would not enrage by its triviality?
Take Annie Dillard’s final paragraph as an instruction.