Define A Few Sandwiches Short Of A Picnic Meaning

A Few Sandwiches Short Of A Picnic
Someone who is not altogether in the mental sense; nevertheless someone who can be considered a blundering dumbass.

Dude 1: Why is that guy rolling little pieces of crap into shapes?
Dude 2: I believe he is "a few sandwiches short of a picnic" better let him be.
By Lexine
A Few Sandwiches Short Of A Picnic
Someone who is not altogether in the mental sense; nevertheless someone who can be considered a blundering dumbass.

Dude 1: Why is that guy rolling little pieces of crap into shapes?
Dude 2: I believe he is "a few sandwiches short of a picnic" better let him be.
By Melisande
A Few Sandwiches Short Of A Picnic
When someone forgets to pack all the sandwiches for a picnic. Doesn't that really piss you off.

Oh dear Giselle, I'm afraid that we are a few sandwiches short of a picnic, we will just have to manage on caviar and champange.
By Cordelie