I’ve been a lawyer for 24 years. That’s fewer than many, but still long enough to have seen my share of complex legal issues. I recently came across one that challenged me more than any I’ve ever faced.

I purchased a self-serve fountain Diet Coke at a fast food restaurant near my work building. I took it to my office and drank it. I then left the building for a meeting – an hour after purchasing the Diet Coke. I was interested in another Diet Coke. Here’s the issue: Did I still have refill rights in the soda?

While it had only been an hour since my purchase, I had left the restaurant and traveled about a block away. Were my refill rights extinguished the minute I exited the restaurant or, given how recent the purchase (indeed, the ice in the cup hadn’t even all melted), could I still walk back in and visit the fountain soda machine as if I’d never left?

I know. It’s an absolutely fascinating question. I have been posing it to many people and the answers have gone both ways. [Best answer – time stamp the cups and refill rights last for a certain period.]