Nuff said.
Dont know what you mean, but yep, it’s important to always save your stuff. When something gets lost, there is a chance that you can probably find an autosave or backup file -> documents/unrealprojects/your project/saved 
Homer Simpson voice: “Did somebody lose all their work? Doh!”
A lightning hit somewhere near my house and my motherboard got fried. Thankfully my harddrive was not damaged. So yeah, always back up and use a source control.
I have modified my neurological pathways in such a manner that I hit ctrl-s after every action, it is unavoidable. And then every time I close a project, I have an uncontrollable impulse to upload everything to a cloud storage. The only issue with this system, is that the automatic “automatically save changes every x minutes” upon creating a new project option really ticks me off > <
Are we related? =P