I don't think i ever have something fully maximized (aside from games, though even then sometimes i play in windowed mode). Even when i do maximize a window (which isn't often but some programs like Krita work better like that), the dock and miniwindows (i'm using Window Maker as my window manager) still take their own space and the background shows through. Also i often have a bunch of terminal windows minimized, then i forget about them and open new ones until at some point i go and garbage collect them :-P