To illustrate this point more. I used to work in a company where everyone had to submit their timesheet via docs. And if you did not keep a link or copy or whatever they call it of your own sheet, it's essentially impossible to search for it, because now there are 1000s of identically named documents.
It also happens when legal tries to share a generically named file with you and you lose the link, so you search for it and find a file that looks like it, only to realise that is HR's own special copy.