Related:

• Why is there air? To fill yours head.
• The emptier the pot, the quicker it boils.
• Swell-head: Nature's frantic effort to fill a vacuum.
• The more you hate a song, the harder it will be to get that song out of your head.
• hrough the intercom] Attention, everybody... um...
  oh... uh... Work harder, bye!...
• Buy a goldfish bowl and fill it up. Stick your head in it for practice.
  The goldfish are optional. -- More things to do as preparation for life as a mermaid....
• or I'll fill you so full of lead we could sharpen your head and call you a pencil!
  -- Amy to Edmund : Amy and Amiability...
• Think harder.
• It's getting harder and harder to act weird. -- Zippy the Pinhead