put on (one's) thinking cap(redirected from putting on his thinking cap)
put on (one's) thinking cap
To begin thinking or considering very carefully and seriously (about something). If we all put on our thinking caps, I'm sure we can come up with a way to earn enough money to go to the baseball game this weekend. A: "Well, boss, what do you think we should do?" B: "Just let me put on my thinking cap for a minute."