Good take on the theme ... hits close to home for all of us.
I had to rummage through the glove box to find an old 1GB card (1st use in years) on a recent (remote) shoot when I realized I had left my 4's & 8's behind. I had to reduce file sizes, but it was for some web work anyway, so I survived it.
I always leave a card in my camera to prevent such occurrences so I've never forgot a card, but back in my film days I shot half a vacation without loading any film in my OM-1!! Still kick myself when I think of that!