Who said "I know exactly what I'm doing... most of the time."?

This quote is attributed to Kelso.

I know exactly what I'm doing... most of the time. - Kelso

"I know exactly what I'm doing... most of the time."

Kelso Humor

"I'm not stupid, I'm just not thinking."

"That's what I love about these high school girls, man. I get older, they stay the same age."

"I'm a sexy beast."

"My brain is on fire."

"Never underestimate the power of a good laugh."

"Laughter is the best medicine."

"A good laugh is the best medicine."

"Laughter is contagious and wonderful."