What’s the last thing you let yourself be wrong about?

I spent three hours yesterday arguing with a nurse about whether 'dyspnea' is a medical term or just fancy jargon. I was dead certain it wasn’t, and she kept saying yes, it’s in every textbook. Turns out I was wrong — and I felt weirdly proud of being wrong. Like, finally admitting I didn’t know something without apologising for it. What’s the last thing you let yourself be wrong about, and did it feel like a relief?