One of my former mates was a trolley boy in Asda. He was not academic at all, but he was sensible, reliable and by no means stupid. Also rather good with cars.
He had an excellent work ethic (but would freely argue with a manager if they asked for something unreasonable) and later became a messenger in the Home Office which was a decent job.
So never underestimate trolley "boys" (quotes as some are girls) - everyone has to start somewhere and some people start as that :)