Not playing with a full deck

 

Everyone’s heard, “He’s not playing with a full deck,” and everyone knows it means that “he” is extremely ignorant — if not ignorant, then certainly clueless.
It’s surprising how many English assertions suggest such cluelessness. Let’s look at a few.
His driveway doesn’t go all the way to the road. She’s two potatoes short of a bushel. She’s a few floats short of a parade, or a few camels short of a caravan, or a few colours short of a rainbow.
These sayings all mean the same thing. We have so many of them because people strive for originality. That Jake’s elevator doesn’t go all the way to the top has been said thousands of times, but Jake’s elevator must once have seemed an improvement on, “His stairs don’t go all the way to the attic.”
The trouble with creating fresh, bright expressions is that if they’re really fresh and bright, they instantly catch on and become clichés.
When TV was new, remarking that Fred’s antenna didn’t pick up all the channels probably seemed a brilliant thing to say, just as, noting that Tim’s not the sharpest knife in the drawer must once have been innovative.
Such put-downs are very old. As early as 1563, people were saying, “He knew not a B from a battledore nor even a letter of a book” (Acres and Monuments of the Latter and Perilous Days, John Foxe).
Back then, such an expression usually referred to illiteracy, but by the time Shakespeare’s Hamlet declared, “I know a hawk from a handsaw” (1599 or 1601), this type of aspersion referred to intelligence.
“He doesn’t know beans,” is thought to be of 19th century U.S. origin. If so, it refers to Boston baked beans and the fact they’re made with one very specific type of bean. However, some scholars think, “He doesn’t know beans,” arose from the British phrase, “To know how many beans make five.” This centuries-old idiom refers to the custom of using beans to help children learn to count.
Although statements of this type are put-downs, they’re never directly said to the person who’s not firing on all cylinders and, subsequently, are seldom viewed as insults.
Insult (literal meaning, “to leap on”) is from the Latin insultare (to leap). The primary dictionary meaning is, “to speak or treat in a callous or contemptuous way.” 
But insult also means, “to reveal a disdainful estimate of.” So, when we say, “Harry doesn’t have all his cornflakes in the same box,” we’re insulting Harry even in his absence.
We all do it. So, here are a few more such insults to add to your repertoire:
• His river doesn’t run all the way to the sea.
• She’s missing a few rungs in her ladder.
• Her pilot light has gone out.
• He’s one sandwich short of a picnic.
• He only has one oar in the water.
• He’s a few countries short of an empire.
• She’s a few stitches short of a tapestry.
• He’s a few clowns short of a circus.