Who said "Sometimes you need solitude to understand yourself."?

This quote is attributed to Guardians of the Galaxy.

Sometimes you need solitude to understand yourself. - Guardians of the Galaxy

"Sometimes you need solitude to understand yourself."

Guardians of the Galaxy Solitude

"I'm your friend, man. I do this because you're my friend."

"Sometimes the thing you fight the most is the thing you need the most."

"We are Groot."

"You're welcome for saving the galaxy, by the way."

"Sometimes being the best means being the loneliest."

"Solitude gives us time to reflect on what matters"

"I'm not good with people, never have been."

"I feel like I'm disappearing."