When I was working or BMI this gave me a good laugh:
Pax: Excuse me how much does a vodka and coke cost?
Me: Our service is complimentary madam.
Pax: So how much does it cost?
Me: Madam, a complimentary service is one that doesnt cost anything.
Pax: Ohh I`ll just have a coke then.
Is it the altitude that causes this kind of premature dementia or what??