In all my years of working with fly fishermen, something they finely convinced me of was that they really didn't have any bad habits, they had poor understandings and gaps in their information. Once confronted with the definition of a 'bad habit', they realized they didn't have bad habits they had voids in their understanding, not bad habits. I never had a student or charter customer who chose to perform poorly even tho they knew how and could do better. There's a reason I don't use the word 'casting', and it goes directly to the reason my charges don't have bad habits.