My Passport corrupted although nothing appears to be wrong

Last night my external hard drive was running fine and today when I tried to access it I was given an error message indicating the drive was corrupt and I needed to format. Having once dropped an older hard drive I immediately downloaded Recuva which has had a look through My Passport and it has found all files present, correct and uncorrupted. So I do have the option of slowly extracting it all to a separate hard drive reorganizing it and then reformatting and resaving all my stuff. Obviously I would rather avoid this time waste.

Can someone explain why it’s done this (It’s been neither dropped or removed unsafely)? Is it likely to do this again? And is there something I can do to just regain access again without needing to format?

The one thing I can think I may have done wrong is leave it plugged in continuously, even when turning the computer on and off.