I'm still relatively new at it so I'm having fun with learning various knots and practicing on a few different lengths of rope I have at my desk. Inventing a new knot would be great, but I'm not at that level yet.

It's more of a casual hobby, but knowing knots can vastly enhance other activities. The spatial challenge of learning the knots is what's most appealing to me right now.

I've got two books at the moment, the 'Ashley Book of Knots' which is a classic, and the "Everything Knots Book".