Why Do We Say That

KNUCKLE UNDER
Once knuckle meant any joint, including the knee. To knuckle under meant to kneel in submission.

RESTING ON YOUR LAURELS
In the ancient world winning athletes and other heroes and distinguished people were given wreaths of laurel leaves. If you are resting on your laurels you are relying on your past achievements. If you need to look to your laurels it means you have competition.

HOOK OR BY CROOK
This old saying probably comes from a Medieval law which stated that peasants could use branches of trees for firewood if they could reach them with their shepherds crook or their billhook.

POT LUCK
In the past all kinds of food went into a big pot for cooking. If you sat down to a meal with a family you often had to take 'pot luck' and could never be quite sure what you would be served.

NICKNAME
This is a corruption of eke name. The old word eke meant alternative.