I haven't had that many passengers sayin things like that - only the odd one but I always reply with the fact that if there was a fire on the ground, the fire brigade could be called, if someone took ill on the ground, an ambulance could be called. Some people are just rude - they have no idea of the exams + intense training we have to go through + some are so
ignorant that they wouldn't even listen if we tried to explain!
