The theory of muscle confusion in body building is a marketing gimmick and has no scientific basis. Muscles (and dicks) don’t get “confused”, nor do they “guess”. They respond in predictable ways to a certain amount of stimulus, depending on each individual body’s genetic potential. The most effective body building regimens are those that incorporate adequate amounts of rest and nutrition and avoid over training. I suspect the penchant for changing up routines has more to do with the inability to stick with a consistent workout than bigger or faster gains. We all have a limit on our genetic potential, whether it’s body building or dick stretching, and as you get closer to that potential the rate of your gains will naturally decrease. As in body building, avoiding injury and getting sufficient rest contribute just as much to the process as PE exercises do.
(Sorry to be so sensible.)