Do you want to fill your head with useless knowledge?

To give me something to do with useless knowledge: You probably know the feeling.

It is useless knowledge, really, as the family lost its land and prestige when the male heirs died out.

Only this shows you how useless knowledge is unless you apply it.

"Then keep your passion for useless knowledge to yourself."

"Please go away," I said, "and stop showing off the useless knowledge you get from number plates."

"Then what makes you want useless knowledge enough to pay a million marks for it?"

You never know when a little useless knowledge is going to come in handy.

She was a teacher of useless knowledge, and speaks more than one tongue.

That may seem obvious, but it is useless knowledge unless implemented.