I agree with all these disparate statements! In a way one should, however, not do what is comfortable. I had a 50 only for around 20 years. I never fully understood it until I had a 35 for a few years. I remember how uncomfortable I was with the 35 at first, consciously trying to float the main subject in that wonderful context, and learning to get in closer. Now that has become second nature, sort of, and I appreciate the medium telephoto of the 50, which I would never have viewed in that way otherwise. My next unsettling experience was getting a 25 which was another world altogether, and after a few weeks I got some good shots and now love that focal length. And yes, it has deepened my understanding for the 35mm focal length. Time for a 21 I think.