The senior citizen decides to go back to school to improve his mind. During registration his advisor suggested he take social studies, history, calculus and logic.
"Why logic, what is that" he inquires.
His advisor tells him it helps clear thinking and deductive reasoning. The senior is confused so the advisor offered an example:
"Do you have a weed trimmer?" he asks
"Yes" says the senior
"Then I can deduce that you have a yard."
"Yes, I do have a yard"
"So if you have a yard, you must have a home."
"Why yes I do have a home"
"If you have a home you likely have a family"
"Why yes, I do have a family, a wife and two children," says the senior.
"If you have a family I can deduce that you are heterosexual."
"Wow, you can tell all that from my having a weed trimmer!?"
The senior is trying to impress his peers about retuning to school, and tells them he is taking some subjects including logic.
One of them asks what logic is and what good it is.
He replies, "Here, I'll show you."
"Do you have a weed trimmer?"
"No" replies the other.
"Well then, you're queer."