OS X :: Little Checkbox Said Ignore Permissions

I had a folder (called "Other") with read and write access for Joseph (Me), everyone, (unknown), and Joseph (Me, again), but for some reason I couldn't write to the folder - I only had read access even though three forms of me had read and write. I tried changing the permissions of the parent folder to read and write (which they already were for everyone, but I added my account too for the hell of it) and then applying it to the enclosed items, but that just added "wheel" to the Repairing permissions did nothing, I ended up just setting my entire Macintosh HD to read and write for everyone and a few other people, then applying to enclosed items. That worked, but then for some reason it changed my external hard drive's permissions to "Custom" for Me, Me, unknown, and everyone. I can't access my external at all now, and nothing happens when I try to change its permissions. There was a little checkbox that said "Ignore permissions"