I'm using a Mac again at work. Mostly it's fine, but DAMMIT, those keybindings all make NO SENSE AT ALL.

Browserhistory on CMD-Y
Switch Windows of the same app: CMD-<

And don't get me started on cursor navigation by keystrokes...

CMD-Q to quit makes at least sense, but annoying as hell if your muscle memory assumes an @ there - thankfully, that can get fixed by Karabiner...