It's probably because you have "Don't show hidden files, folders, or drives" chosen in Control Panel/Folder Options. In View, change it to "Show...", then click Apply, to check it out.
It is safer to have hidden and program files not showing, as it prevents accidental deletes. Sort of, protect yourself from yourself. And there's no real reason to see them.
Nothing dangerous, I think. I do marvel the size of your User Folder, though - mine is 3.62Gb. But then, I'm a modest man.
You could do well with a clean up, CCleaner or Advanced System Care,
http://www.iobit.com/advancedsystemcareper.html. If you haven't used them earlier, default settings is a good choice.
Best of all.