Now here's my idea that I evolved with my thinking-cap—I mean night-cap—on!
"And this head of mine would have to put on its thinking-cap," he pursued jovially.
We are a little too inclined to doff the thinking-cap at the first opportunity.
But I had my New England "thinking-cap" firmly set on my shoulders.
Tell me what you know and then my 'thinking-cap' may be put on to ...