"What are you doing?"
"I'm cataloging my movie collection."
"What for? You've already arranged all your films in the shelves in alphabetical order according to the original titles."
"This is a genre list."
"If my friends want to borrow a certain kind of movie, I can immediately check for something recommendable."
"As far as I can remember, the computer was bought for me - and so that I'd learn to use my time for something useful."