It is good to know that common flight routines are actually really important to keeping everyone safe, so you have a little more motivation to follow the rules and to make sure that everyone around you is following the rules. Some of the procedures for takeoff that frequent fliers are all too familiar with include stowing your personal item bag under the seat in front of you, closing the tray table, and opening the window shades. Personal items and electronics are stowed since they could be incredibly dangerous if they end up flying through the cabin in an emergency. An open tray table could block the way if we need to get out fast, and cabin lights are also dimmed to help our eyes get used to the dark, just in case we need to leave the plane in darkness. Passengers also aren't asked to open the window shades so everyone can enjoy the view, but instead, the window shades need to be open so emergency personnel could get a good look inside the plane from the outside in the case of a crash landing.