The facilities on airplanes...
Have you ever been waiting so long that you started knocking on the door and found out someone was still in there taking like 30 minutes? Why?
Have you ever had a seat next to the toilet on an international flight and had to smell the "dairy air" (as John Heald would say) for 12 hours wafting out everytime the door opened?
Have you ever been on an international flight and all the toilets have stuff left in them that didn't go down and absolutely no one is willing to fix it?
Doesn't it make you wonder why each flight doesn't assign at least one attendant as the "sanitation engineer?"
Have you ever used the "lift the occupied sign" trick to unlock the toilet from the outside only to find someone was still in there?