Who said "Sadness is just as important as happiness in life."?

This quote is attributed to Bing Bong.

Sadness is just as important as happiness in life. - Bing Bong

"Sadness is just as important as happiness in life."

Bing Bong Wisdom

"I'm Bing Bong, Riley's imaginary friend! Nice to meet you!"

"Imagination is what makes life worth living."

"You can't fake being happy when you're really sad inside."

"Sometimes the best memories are the ones that make you laugh and cry at the same time."

"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."