Somehow, the magic pixie dust between my iPhone mail app and Gmail has become contaminated, and now my iPhone is showing me as having -1 unread messages (and if I have 1 unread message, then it’ll show 0 unread messages)
I think this has something to do with the fact that I get two messages a day from my bank (with checking and savings balance) with Gmail always sees as a single message with a reply, and mail sees as two seperate messages. I think deleting one of thise on my iPhone a week or so ago caused a ripple in the space/time/email matrix.
I’ll have to do some Googling to see if anybody else has seen this. Or just deleted and recreated the gmail account on the iPhone to start from scratch.