I've learned to tie knots hundreds of times. Usually it's the same knot, the one they use to tie fenders on boats, which my friend Anthony shows me every time I go on his, and which I use once and then immediately forget after stepping back on shore. Whatever, dude, it's like memorizing state capitols or remembering shit my girlfriend tells me: only important when you know there's going to be a test. For the knots at least, PRO-KNOT has developed a sweet little study guide/cheat sheet that slides in your pocket and weighs less than an ounce.
The Outdoor Knots! booklet is a collection of 20 of the best all-purpose rope knots consolidated onto 6 waterproof plastic cards and bound with a brass grommet. Each knot has both written and illustrated instructions for tying. The booklet includes the following knot how-tos: Bowline, Square Knot, Water Knot, Rolling Hitch, Clove Hitch, Sheet Bend (doubled version too), Trucker's Hitch, Mooring Hitch, Cleat Hitch, Tautline Hitch, Buntline Hitch, Prusik Knot, Butterfly Knot, Half Hitch, Constrictor Knot, Double Fisherman's, Figure Eight, Bowline on a Bight, Sheep Shank, and Timber Hitch.