In my first year I was taught about the slide rule. They said, "The slide rule is important. Without it you can do nothing. The slide rule is the modern weapon of efficiency. With the slide rule you can get from here to the stars. Buy it, use it – your slide rule!" Within one year it was, "Burn the slide rule. The calculator can add up with none of this fucking sliding the shit around and working out where that bit in the middle goes. Smash it over your head."