I'm with Galldune on this one.
If it's something that interests me, I figure out everything I can on it. Once it's come to the point that I've learned everything I could about it, it's on to the next interest.
If I'm with a group of friends and they start talking about sports, I pretty much sit back and go off in my own world. Once a gap in their convo seems like they're done, I move it into a subject I care about talking... usually completely off topic from sports.
If it's something that interests me, I figure out everything I can on it. Once it's come to the point that I've learned everything I could about it, it's on to the next interest.
If I'm with a group of friends and they start talking about sports, I pretty much sit back and go off in my own world. Once a gap in their convo seems like they're done, I move it into a subject I care about talking... usually completely off topic from sports.