I'm so glad I'm not a dentist. How many times does someone say, 'Oh, Doc, it felt so good when you were drilling my teeth'? Never. But when you give someone a wonderful cookie, you put a little of yourself in, and you see someone's face light up - that's immediate approval.
In college I had a weekend gig at a restaurant, a solo thing that was the best practice I could have ever had. That's where I learned to coordinate my singing and my piano playing.