1. Airplanes. End of story.
  2. Seeing the dust on top of refrigerators.
  3. People in grocery stores ask you to get things off the top shelves.
  4. Europeans used to be very short and haven't remodeled since the 1300's. Hallways there are not tall enough.
  5. When other people walk under branches without ducking and you go straight into them.
  6. Being taller than the bathroom stall and having to duck down so you're not staring at someone pooping