Because, let's face it, meetings are long. Like, really long. And if you don't take a break, you'll be that one person who really has to go.
Step 1: Pretend to take a phone call, Step 2: Stare out the window, or Step 3: Faintly whisper 'I have a meeting' to get out.
More meeting hacks: Pretend to have a panic attack, Accuse the organizer of being a dictator, or Suggest a jaunt in the park.