In retrospect, running four miles with shoes but no socks was a bad idea.
But then, I wanted to run, and hadn’t brought socks. What was a fleet-footed footwear-forgetting flip-flopped fellow to do?
As you may have realized, the subject refers to the prior sentence.
What were you thinking? You should have brought bandages. Or just run without shoes. Be one with the wild…
Somehow running without shoes on a treadmill just seems wrong…