Names
Names
Cueball (thinking): I hate it when I don't know someone's name, but it's been long enough that it's too awkward to ask. [The scene is revealed to be at the altar getting married by a minister to a woman in a bridal dress.] Minister: Do you Rachel, take this man... Cueball (thinking): Aha! Rachel!

Everyone has had moments where they forget someone's name, even the name of someone pretty important. This doesn't often happen with one's own significant other, however, hence the joke.
Cueball has been in a relationship with someone but does not know his girlfriend's name. He knows that the relationship has progressed to the point where asking for her name would be awkward and impolite, and so he waits for someone to call her by name. Cueball is excited when one finally does, only to reveal that they are in the middle of a wedding ceremony. It is hard to be in a relationship with someone if you don't know their name, and for said relationship to progress to the point of a wedding is simply incredulous. [ citation needed ]
It's sometimes tricky to say the right things during an introduction, and while making sure you don't make an incorrect response (replying to the question "How're you doing?" with "Not much," for example, mishearing the question as "What are you doing?"), one can sometimes forget to pay attention to the actual important part of the introduction: the person's name. And it's awkward to ask someone for their name when you should, by all rights, already know it.
Forgetting people's names is a frequent symptom of various social anxiety disorders, but it can happen to anybody at any time.
Cueball (thinking): I hate it when I don't know someone's name, but it's been long enough that it's too awkward to ask. [The scene is revealed to be at the altar getting married by a minister to a woman in a bridal dress.] Minister: Do you Rachel, take this man... Cueball (thinking): Aha! Rachel!
