Regardless, the boy enjoys his job, as well as the resultant income (it gives him enough to buy comic books), however meagre it might be, and spends a few hours per week merrily bagging groceries and helping people carry said sacks full of groceries out to the car.
Well, the grocery store has just come off a very successful fiscal year, and so the owner decides to expand, and into with the deli (which you'll find in any grocery store worth its beans) he puts a smoothie station.
This smoothie station was different, because the juice they used came from fresh fruit (usually oranges) which were cut up and run through a juicing machine right there at the counter.
The boy, schooled by years of advice from his father ("Always look for a chance to grow and move up, son! It's the only way to get ahead in life"), decides to ask his manager to transfer him over to the smoothie station.
"I've done such a good job as a bagger, and, well, I think it would be nice to try something different. I know how to work the machine and everything."
The manager considers his plea briefly, but says "No, I think you will stay where you are."
"But why? Have I done something wrong?"
"You haven't done anything wrong. In fact, you're a great worker. But the simple fact of life is, son, baggers can't be juicers."