We live in a world of rules. We see them everywhere when we travel by plane. No liquids! Wait here! Turn off your phones! But what about those unspoken rules — the ones that aren't written down and no one is exactly sure about. A travel expert from the US has been explaining her unspoken rules for the airplane journey. TV host Samantha Brown shared her rules with CNN, including one that makes the middle seat feel a little more comfortable. According to Brown, if you find yourself in one of the middle seats on a plane, you should get both of the armrests to yourself. Sitting in the middle isn't always very popular and so Brown says these passengers should get "anything they want." That means even if the people on the outside begin using those armrests, the person in the middle has the right to "slowly push them off!" Brown says she likes the aisle seat best because she feels she has more space. She added that people sitting by the window should have control of the window blind — whether it's up or down. And the others don't have the right to decide! One thing that can make some passengers angry is people in front putting their seats back. Brown has a rule for this — if the journey takes less than three hours, she doesn't put her seat back, but she does if it's a longer trip.