Learning When

“Why does that tree have two tops?”
“It used to be a man with two heads.”
“Men don’t have two heads, Grandma!”
“This one did.”
“Why did he have two heads?”
“He only had half the brains he needed.”
“Needed for what Grandma?”
“To know when he should have left me alone.”
“Is that why you turned him into a tree?”
“Yes it is. Even two brains weren’t enough for him.”
“That’s a funny story grandma. Can I grind up the salamander newt this time?”