Penny Hofstadter: Helium.
Sheldon Cooper: Yes.
Sheldon Cooper: Taylor Swift.
Penny Hofstadter: Yes.
Penny Hofstadter: Pi.
Sheldon Cooper: Yes.
Sheldon Cooper: Kardashian.
Penny Hofstadter: More specific.
Sheldon Cooper: Khloé?
Penny Hofstadter: Yes!
Sheldon Cooper: Ah! See, I remember because if it looks like Kim, it's Kim; if it looks kinda like Kim, it's Kourtney; if it looks nothing like Kim, it's Khloé.