Read the excerpt from "Mending Wall."Spring is the mischief in me, and I wonderIf I could put a notion in his head:“Why do they make good neighbours? Isn’t itWhere there are cows? But here there are no cows.Before I built a wall I’d ask to knowWhat I was walling in or walling out,And to whom I was like to give offence.Something there is that doesn’t love a wall,That wants it down.” I could say “Elves” to him,But it’s not elves exactly, and I’d ratherHe said it for himself.What is the speaker’s mood in this excerpt?