Sometime and somewhere, I will find out that people just don't know what to say and mistakenly saying something that shouldn't be said.
Let's start with my experiences.

I was about to buy a take-away whole roast Oporto 's chicken for dinner with friends at home.
Me: "Can I have a whole roast chicken?"
Oporto's staff: "Okay, which sauce would you like?"
(the staff is a young man)
Me: "Mild please"
Oporto's staff: "Err.. eat here or take away?"
Me: .... (really can't say anything for a second thinking if anyone is crazy enough to finish a whole big chicken in one go)... "Take away please."

And let you know that this chicken is bigger than "ayam kampung", it's like a bigger version of Kentucky Fried Chicken back in Indo.

Another version: I was buying a set of gym suit plus a shoes in one shop because it had a cheap price offering. The staffs were nice and kind. However, buying a set like that in one shop would be a bad idea. Why?

Me: (buying a set of gym suit and a shoes since my only one sport shoes was stolen around 4 days before and I think better I'd buy a set of gym suit for later use, then I was going to pay for all in the cashier).
Staff: "Are you just joining a gym?"
Me: (thinking why this staff was asking me...) "Nope, actually last year."