Crook in the Lot
There is a crook in the lot of everyone. There is vexation bound up in every person's lot of life, a skeleton in the cupboard of every house. A crook in a stick is a bend, a part where the stick does not run straight, hence a “shepherd's crook.” When lots were drawn by bits of stick, it was desirable to get sticks which were smooth and straight; but it is very hard to find one without a crook, knot, or some other defect. Boston has a book entitled The Crook in the Lot.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894