All you need is a star chart and a sense of wild abandon.

What's your sign? Born in March? Yes, looks like you're an... Ursa major! What good fortune!

I was chatting with a bartender about my telescope a while ago, and the woman sitting next to me asked me when my birthday was. I told her the month, and asked why. She said “it sounds like you know a lot about astrology.” I said “oh no, I’m into astronomy,” to which she replied “same thing.”