Who said "Running away is easy; solving mysteries is hard."?

This quote is attributed to Scooby-Doo.

Running away is easy; solving mysteries is hard. - Scooby-Doo

"Running away is easy; solving mysteries is hard."

Scooby-Doo Perseverance

"Scooby-Dooby-Doo, where are you?"

"Ruh-roh!"

"Like, zoinks!"

"Let's split up, gang!"

"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."