Who said "You can't give up just because things get tough."?

This quote is attributed to Goku.

You can't give up just because things get tough. - Goku

"You can't give up just because things get tough."

Goku Perseverance

"I am the hope of the universe. I am the answer to all living things that cry out for peace."

"Even the strongest of opponents always have a weakness."

"I'm not fighting to win. I'm fighting because I have to."

"The difference between our power levels are like the difference between a firefly and the sun."

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."