Stargate Atlantis, Season 4

[Rodney is starting to forget things]

Teyla [to Dr. McKay]:
What is the ratio of a circle's circumference to its diameter?

McKay:
Well, that's pi, it's 3.14159265 etc, etc... Oh, t-that doesn't count, that's easy.

Teyla:
You are a scientist, Rodney, that is what you care about, that is what you will hang on to the longest.

McKay:
Right, right, so... [pause] Wait a minute, doesn't that make me a really bad person?

Teyla:
It makes you the type of person who is going to save all our lives.