That very thing happened to me a few months back. I get together with other (Pagan) women every couple of weeks, very informal mind you. Anyway, we all decide on a topic for discussion before the next meeting, and one of us usually researches that topic and then presents on it. It just so happened that the person who was going to present couldn't make it due to weather, and I had just happened to have brought my brand-new Llewellyn deck, with me.
I volunteered to do it, since I seemed to know more than anyone else there. I went through the Majors, explaining each one, then the minors, and it hit me (ouch), I could read the cards! Our friend who couldn't make it suddenly showed up, and was impressed by my knowledge, and asked me to do a reading for her, on the spot, and I did it!!
I was so excited, I couldn't sleep that night.
Congratulations!