I will forever recommend VoidTools' Everything ever since someone first introduced it to me some few years ago.
It indexes your entire filesystem and allows you to search for files by name (and by content for text files!) and even allowing RegEx searching for file names, and filters for certain file types and the like.
A lot of the time I need to go digging around in some of my old files from backups to find something (that I remember the file name of, but not the path), so it helps there.
It also helps when I need to find the path of something quickly, as I can just find it by name and use the "Copy as Path" context menu option directly from the results window.
... definitely helps as well when I can't seem to keep my files organised for too long and they get super cluttered quickly, skill issue on my part there.