I am worryingly anal about folder/file structures. I even get a bit weird like not liking folders mixed with files in same level (like a folder which shows 5 subfolders and a handful of files). So I find myself making a folder just for two or even one file, until I catch myself and sanity returns.
And i get really itchy about the divisional server at work, which is all over the place as it's "looked after" by secretary with no organisational or IT skills.
My department folders I'm happy with, but whenever I go elsewhere I get a huge urge to tidy it all up and archive all the ancient files and duplicates.