Last year's styles are old hat.
That prank is old hat.
remix culture " more than a bit old hat.
denigrates what is " old hat ", it won't last when it becomes old hat itself.
More sophisticated juniors might also find the story a little old hat.
And most readers find " remix culture " more than a bit old hat.
An old hat and a Christmas goose are the only clues to a stolen jewel.