iPhone 15 pro max went black. First time, but I quickly figured out why…

I’d plugged it in to recharge (I’ve had this phone for a little over a year? I think?), and it decided to update the software, I guess b/c it assumed I was plugging it in for the night. Updated to iOS Version 18.3.1. Read here (and all over) how to start it back up (volume up, volume down, then press & hold side button), and everything’s fine…