Criticism is like water off a duck's back.

He always makes a stick for his own back by procrastinating.

The instructions for assembling the furniture could be written on the back of a postage stamp.

The instructions for assembling the furniture could fit on the back of a postage stamp.

After falling off, it's important to get back on the horse that bucked you.

I want my money back

Miss Sharp put the knife back in the knife drawer.

A bad penny always comes back.

The bad penny always comes back.

He decided to pay back in his own coin for all the insults he had received.