This poster was recently auctioned at Bonham’s auction house in London where it was expected to bring $1,000 to $1,500, but reached only $700. (Still, a lot of money for a poster that was only $2 when it was new.) Princess Pennie and the wizard were 9 years old when this poster was introduced, but by the time they met in Junior High, it was everywhere. Bonham’s writes,

Robert Crumb’s Keep on Truckin’ drawing was one of those events where something seemingly trivial and passing escalates into a cultural moment. First included in Zap Comix, it was embraced by young people. Rather quickly, the image and phrase began to show up on posters, t-shirts, patches and badges, much to Crumb’s consternation. After years of litigation, Crumb was able to secure the copyright to Keep on Truckin’. This is a vintage, licensed version of the poster in rare condition.”

When the “Keep on Truckin'” fad had begun to fade, Eddie Kendricks (previously of the Temptations) brought it back for a moment with a hit song.