be one sandwich short of a picnic(redirected from be a couple of sandwiches short of a picnic)
be one sandwich short of a picnic
To be not very intelligent or of questionable mental capacity. It can appear in many different forms and variations (for example: a few bricks shy of a load, a few cards shy of a full deck, etc.) He says he's going to start a business selling bees as pets. I think he may be one sandwich short of a picnic.