Who said "I've learned that saying no is as powerful as saying yes."?

This quote is attributed to Peggy Olson.

I've learned that saying no is as powerful as saying yes. - Peggy Olson

"I've learned that saying no is as powerful as saying yes."

Peggy Olson Wisdom

"I'm not just a secretary. I'm a copywriter."

"You're thinking about this all wrong. It's not about what you want—it's about what they need."

"I didn't come this far to be somebody's girl."

"Every time we get a chance to do something, it matters."

"I'm not angry, I'm just disappointed."

"The best things in life are free."

"You can't have everything in life, but you can have what matters most."

"A woman's intuition is rarely wrong."