The thing is, Dropbox treats their version as the primary copy. For instance, I added several directories to Dropbox, and decided that I didn't want it syncing

The thing is, Dropbox treats their version as the primary copy. For instance, I added several directories to Dropbox, and decided that I didn't want it syncing a few of them. I de-selected the directories under "Selective Sync" and it removed them from my computer - even though my computer was the original source.