Dr. Bliss queried about challenging and difficult things which can be intrinsically rewarding despite their effort, complexity, difficulty.
Making music has to be the highest of all hobbies, and understanding music perhaps comes second, but fly-fishing is one of the more humble but still somewhat complex things as are most absorbing hobbies, like woodworking to photography to baseball. Anybody is blessed to have one or two hobbies.
For those to whom fly-fishing is a mystery, here's one example of complexity: Fly Fishing Knot Tying Basics.