Dad's better, but Still in the Hospital

When Mom was in the hospital, she wasn't the best patient. I wondered what was the fewest number of times I could visit and still be a "good daughter." Dad is so fun to be around that I find myself wondering what's the most visits I can make in a day. I can't remember most of his jokes, but the following is typical. A doctor came into Dad's room while I was there and asked a bunch of questions and listed to his heart. "Who was that?" I asked when he left. 

Dad: The kidney doctor. 

Me: I thought your kidney doctor was a woman.

Dad: I have two kidney doctors. But, I have two kidneys, too!