Presentation - topic of choice

I have to attend an interview with a law firm, which requires me to give a 10 min presentation on a topic of my choice (non-legal), using no presentation aids.

I have never given a presentation before. Some research indicates that I shouls stick to 3 key points, and delivery method shoudl be to tell them what I'm going to say, say it, and then tell them what I've said.

But I cannot think of any subject matter to speak for 10 mins on. I have no especially interesting hobbies and have not been on any unusual holidays recently. I am scrabbling around for something to speak about. What sort of things do other people in this situation choose?