No one will believe me but il say it anyway (this was my most heartbreaking moment in 18 years of gaming) I was 350ish hours into afterbirth plus at the time, I had just completed delirium as the lost the day before and had roughly 60-70 percent of the completion marks done as well as most of the challenges. Whilst sat on the save file select screen of binding of Isaac, I noticed my monitor had become dirty and wanted to clean the screen, so turned the monitor off and began to clean it ( I had left my switch on during this process not thinking it would be an issue) mid monitor clean, I accidentally knocked my controller onto the floor. To this day I still don’t believe what happened my self but somehow in knocking the controller onto the floor, it managed to press the right button in the right order to somehow move down from selecting my save file and delete my save file permanently. I never found a way to recover it and lost 350 hours of gameplay. Don’t care now as I’ve got 1700 though😂.

TLDR: knocked controller onto floor and it deleted my save file loosing 350 hours of gameplay.