Have you ever made a mistake? I made a huge one the other day, but was saved! So my cautionary tale is being shared, not to paint myself as incredibly stupid but to demonstrate that even being that, one can be incredibly lucky.
The other day I was doing some cleaning up and moving things on my computer, folders that were also being synced to a cloud site. Long story short, I ended up deleting not only those on my own computer but also those on my cloud site. One minute I had folders of information [much important stuff] and the next, poof!!!, everything gone. Totally.
One lesson: if you're syncing with a cloud site, don't delete your computer data because it'll sync and overwrite the cloud site copy too [I compounded it by also cleaning out the deleted files off the cloud site]. The cloud site is now clean, but that is what caused the problem.
Fortunately, I have a Mac and am running OS X and knew that I kept TimeMachine backups. TimeMachine is part of OS X and does an hourly incremental backup to an external drive so that when you act stupidly, you can go back in time and correct the problem [if you set it up right!]. So, with some trepidation, I went to TimeMachine and went back in time to a few hours before my screwup. I found the now-missing folders and restored them to my computer. You can choose to replace/overwrite or to save both and I always choose the latter, figuring I can clean off the 'original' later.
I am here to report success. Everything in those folders has been transitioned back onto the computer and onto the cloud, to which it syncs.
Lessons learned: always always always backup incrementally and don't work with your computer and data in the wee hours of the morning.
