Unexpected events like having a good relationship go bust or losing saved progress in an almost completed task can be really daunting. For a few moments, it saps the energy outta you - especially the realization of having to do it all over again and the feeling of uncertainty that starting over would make any difference in the end. Best be avoided.
However, from a different perspective, starting over can also be exciting and really should be celebrated. Starting over means you've not given up yet and that's really important. You're giving yourself another shot at success. But this time, you're better prepared, you'll avoid lots of past mistakes and achieve more within a short time.
In the words of Chico Xavier;
"Though nobody can go back and make a new beginning, anyone can start over and make a new ending.”
Setbacks don't always mean ultimate failures. They're just an invitation to push harder. You'll win by starting over.