It's one of the most common things we do, and one of the quietest. We measure how we feel on the inside against how everyone else looks on the outside. Their highlight reel against our raw footage.
It isn't vanity. It's just how attention works — we see other people's surfaces and our own depths. The comparison was rigged before it began.
You already know this. The trouble is that knowing it doesn't switch it off. What helps isn't the resolve to stop comparing, but a smaller, truer measure: were you a little better today than you were, on your own terms?