It is not easy to become knowledgeable enough to be called an Expert. Right now I hold that title for small animals, birds and reptiles at work. I'll admit to having learned a lot working at Petco, but there is so much to know about these animals that I don't know if I should have the title of expert. So I do what any so called expert does. I keep learning more!
Now I'm working on becoming the Companion Animal Expert which means I have to learn fish as well and I have to know all the sections well enough that if one of my coworkers has a question I will have an answer or know where to look to quickly find it. I even asked for Freshwater and Saltwater Aquariums for Dummies for Christmas now I have even more reading to do lol.
Go ahead ask me a question if I don't know the answer I"ll find it!