Class on programme management. We are using Microsoft Project to schedule a construction project, and some boys are complaining that the software is doing weird things, spanning short tasks into long times and they don't understand why.
The tutor looks at them and goes, "Remember, boys: you put garbage in, you'll get garbage out."
He is meaning it as "the software will do what you're asking it to do", whereas I am sitting here and thinking, actually, that sums up life in general pretty well.
You put garbage in, you'll get garbage out.
With some exceptions, of course. As always :)