Well I can prove I am a rookie. I have been tying on tightly wound thread and chennile type flies. First time I tied on a Sailor's Ant....made with foam cylindrical tube looking stuff....I focused on the knot tying it on....and just held and pulled on the body of the fly to watch and tighten the knot. Dumb. I tore the tail of the foam ant almost completely off. Threw it in the water and a trout hit it and then.....he "went away". NO more tail on the fly. I learned to be a lot more careful how I tie on a fly.