"Sure As I'm Sitting Here"
The song presents several life idioms and backs them up with "as sure as I'm sitting here." There is only one thing human's have in their control, and it is the belief that they exist. The only thing I can prove to myself with inexplicable certainty is that I exist and am. Not sure in what context I exist, but I exist. To try to convey truth by swearing upon your mother's grave, or to bet your bottom dollar, or even to sign a document, none of that holds the same authenticity to you, than the belief you hold that you exist. So to say, "I love you, I swear on my last penny" or "I love you. Here is a document stating that"...holds no candle to..."I love you, sure as I'm sitting here"...as certain as I am that I exist, the only certainty I 'know' to be true, I love you.