Related Clues:

• Use one's noodle
• Get lost in a brown study
• Meditate
• Ruminate
• 47 Down motto
• IBM motto
• 'I need you to remember this!'
• "Use your head!"
• Get ideas
• Something to do twice?
• Use one's noggin
• Use your head
• Use one's head
• 1968 hit for 42-Across
• See 25