Keep on truckin' is a colloquial expression that originated in the 1960s counterculture movement. It became popularized through a famous comic strip by Robert Crumb, featuring a character with the same phrase. The expression is often used as a motivational or encouraging phrase, urging someone to persevere or continue with their efforts despite challenges. If you have any specific questions or if there's anything else you'd like to know related to this expression, feel free to ask!