Let’s talk about the Oura Ring.

That little black circle on my finger that people keep asking about. Maybe because I don’t wear jewelry otherwise, maybe because people are unsure whether it’s my wedding band (it isn’t), or maybe because they wonder why a smart and self-aware person is voluntarily accessorizing like a Silicon Valley life hacker. Fair questions.

The truth is simple: The Levelhead part of me bought the Oura Ring. The unhinged part of me kept using it.

With its dozen-plus sen...