> They keep them in while ordering and paying for things in stores and supermarkets.

This hit me. I often use headphones during chores, including going grocery shopping. I love human interaction, but not while pickings things into my shopping basket. For years I'd also leave them in when paying (audio paused, of course). It took a cashier tell me I was being rude before I realized. She was absolutely right, of course. I do make an effort to visibly remove my headphones when expecting human interaction now. A big thanks to that cashier, and my apologies!