I KNOW! It's from "We Have A Lot to Talk About."

Lois: It's so beautiful.

Clark: I used to come up here a lot by myself and just ... drift. Not part of the stars, not part of the Earth. Not knowing where I fit in ... till I met you.

Clark: "You don't even know the meaning of the word 'humility,' do you?"

Lois: "Never had a need to find out its meaning."

"Curiosity... The Continuing Saga"