Hmm, I guess the boat I keep at a storage lot is a gasoline cache since I keep the tank topped all winter with added Sta-bil.

And the mixed box of ammo I keep at my friend's house (we hunt together) so if I forget my 35 Whelen or 300 H&H ammo, I don't have to fret that Wally world doesn't carry the ammo I need.

Caches don't have to be exotic. Just a little foresight. YMMV.