This is a question that a lot of my friends ask me. To me, I don't see what is so bad about it.
I wear gloves, glasses and protective clothing so I'm not directly exposed to the germs, blood and saliva. I don't feel it is disgusting at all. I must admit smells will get through to me but it is only on rare occasions that I smell bad breaths; people don't blow at my face!
I think dentistry is actually pretty fun. Not ALL areas of it are as fun of course. The areas I enjoy the most are restorative (fillings, crowns, etc) and root canal. These are things that I can see nice result from and give me much satisfaction.
Long term relationships that I develop with my patients give me even more satisfaction. It is a good feeling to know people trust you with an important part of their body. Much of dentistry involves irreversible alteration of your body!
Dentistry seems easy, but that is because dentists do it as their profession. I remember when I first tried to drill something, it was extremely difficult to control the drill. Now it is just second nature and an extension of my hand.
Performing dentistry that is of high quality is actually challenging. There is a lot of engineering and physics that I need to consider during the procedures, so that fillings last as long as they can.
In the past year or so since opening my own business, I have had to deal with the accounting side of things. Funnily, I ask my accountant, "How do you stand looking at numbers all day?"