Question about an episode…

I’ve been trying to figure out what episode this is for a long time now, without having to watch the entire series from start to finish. All I remember is some psychic or something Dan is skeptic of tells Dan what his embarrassing childhood nickname was…or something along those lines, and Dan goes nuts, saying “Who told you that? Who told you that!!!???”, and then regains his composure and calmly says “I have no idea what she’s talking about”.

It made me laugh my ass off when I was a little kid, and I still quote it from time to time and laugh, but I can’t remember what episode it’s from, or if I’m even remembering it correctly.

If this sounds familiar to anyone please help me out a little bit with the episode title. Thanks!