This pisses me off. Some lady was just doing this the other day in a grocery store and just straight-up having a conversation with a guy about plans for the evening, what movie to get a Redbox and some other boring crap. Full blast, I could hear their conversation 3 isles over and was slowly making my way over to her as I shopped. She ended up walking to the front before I was in her row but there she was, looking as I walked past, she rested her phone on the counter at the cashier, still blasting as the lady scanned the items, still talking and ignoring the cashier.
I only could conclude there has to be some kind of mental illness. It's just weird because she sounded so normal.