Chasing Chewbacca

Much as heroin users 'chase the dragon' in an attempt to fully satisfy their appetite, marijuana smokers 'chase Chewbacca' in an attempt to achieve their goal. Problem is, tolerance builds up and it the dragon and Chewbacca become elusive and harder and harder to find. Hence, they are 'chased.' 'Chasing Chewy' is often used as well.