Rumour: A surgeon who performs the same operation 20 times in a row is no better at that surgery than one who performs that same operation 40 times with other types of surgeries in between.
Truth: This is false. Surgeon specialization (the rate at which a surgeon performs a single type of surgery back-to-back) is very important and can even predict the rate of patient mortality following a surgery. Read more about the risk of death in relation to surgeon specialization here.