My observation about his comment being a mild form of sarcasm was based on the fact that I find almost all of his parables filled with self-evident truth.
Self evidence of sarcasm? But then you also say you aren't sure of what Jesus had in mind, so I doubt anything about what he said would be self evident to you.

I am sure about Jesus having been serious about what he said. He did not play games when it came to truth. He was the most direct and straight forward person there was. From the early years when he began lecturing and even correcting his teachers in school he was bent toward the direction of clear reflection in a world filled with egoic twisting of truth and varying assumptions made about the universe. He did not come to tell a good story and leave the world with a message of sarcasm.
What proof do I have? The experience of having been annointed with the stick of knowledge, and I don't make assumptions.

By the way your sarcasm is noted along with your assumptions.
I was addicted to the Hokey Pokey, but then I turned myself around!!