I have a lot of movies of family events that I am making one movie out of.
As I edit them, I keep the originals in case I want to edit more. Somehow, I ended up with a complete sub-folder with the same folder names. Worse yet, the sub-folder has SOME of the same file names, but not all of them.
There is a difference in size of 39.4 Gb. The top level shows a total of 64.9 GB, while the sub-folder shows 25.5 GB.
See what I mean, Jellybean.