When you say it around people who are generally quick witted, it takes a second for them to grok what you're saying and then they figure out that you're cracking a joke and then they smile, usually laugh.
But years ago I found myself working as an aircraft mechanic. And my cohorts whom I rode around with were very blue collar in language and culture, and several of them had been chosen as "mechanic" because they hadn't performed that well on an aptitude test.
So one day I made one of my famous observe-the-obvious funny statements, and one member of the group whom I'm pretty sure was one of the low aptitude scorers, looked at me with obvious disgust and said, "You must be one of the dumbest people I've ever met."
He didn't understand why I started howling with laughter.