Comments you wish you'd made

You know how it is. Someone makes a sarcastic comment and you come up with a great comeback… two weeks late. Or you come up with the most humorous put-down possible, post it, and the thread’s been locked.

What are your IWISs? ('I wish I’d said’s)

Friend: lots of questions.
Me: answers.
Friend: Are you, or have you ever been a member of…
IWIS: Nyet.

Poster in ATMB (paraphrased): I’ve been banned 5 times. Why? How do the mods know its me?
IWIS: Because you tell them?