25 years ago I was in Orlando Florida for software training. The class lasted two weeks so we were all well acquainted. One day during break I announced I was going downstairs for a pop, would anyone like to join me?
Silence.
Thinking the chatter in the class had drowned out my offer, I repeated it.
Stoney silence.

Finally the instructor said, "In Nebraska where she comes from, they call soda 'pop'".

Then I learned that in Florida, pop was slang for drugs. My face was red!
Now I say soda even in Nebraska.