I’m 40 just today, but I’ve been approaching this threshold with care for some time. I wrote this poem, for example, at least 6 months ago.

I’m in no way surprised by the day itself—aside from the deep (and unusual) sense of well-being that’s suffused me since I woke. I always want to look for the causes of a feeling in circumstance, but aside from certain baselines, honest consideration of the evidence compels me to conclude that circumstance is rarely my direct catalyst.

So what is it, today? I am pleased to leave the question unanswered. I’m 40, and I’m happy. Here’s a poem.