I grew up in a developing country. Dentists had no resources to give anesthesia except for very complicated work, so you wouldn't get numbed when they drilled your cavities. It always hurt and I was terribly frightened of going to the dentist.

When I came to a dentist in the US for the first time while in college, I was so scared I was shaking in the chair. He had to redo some fillings, and I remembered that they had really hurt when I had them done in middle school. But then the dentist saw I was scared and he was really nice and started joking with me ("Are you nervous? Me too! Look at my hands shaking! I'm so nervous!"). Then he gave me a shot and I never felt a thing while he worked.

I was never scared of dentists again and I'm always glad to get those shots, because I know what it would be like without them.