Help! I have an "old mate"

Come on, you’ve had one too. Most people have. That person in your life whose name completely eludes you. You see them all the time, and it’s embarrassing. You should know their name; after all, they know yours, and what’s worse, they use it all the time.

At first, you can let the situation go. But before too long, it’s out of control. Too much time has passed for you to just ask straight out. You could just take a stab, but there’s an almost 100% chance that you’ll be wrong.

Then, something happens and you know you can't let it go any longer.