I'm no expert. It's odd because the more classes that I take, the more dogs that I know the more I realize how little I know. I have much more respect for dogs than I used to and am far more cautious with them. I think that I've gotten pretty good at reading dogs and hence understand when they are stressed.
I grew up with dogs even though my dad was very uncomfortable with them. As an adult, I've had dogs for the last twenty years. I was a certified dog trainer for a brief time and did foster work as well. So I guess that I'm an experienced amateur.