【 So true!】

…Perhaps one could compare an object in programming more to the animate objects of the real world, as opposed to the inanimate objects, except that — unlike real-world animate things — a programming object is supposed to be predictable: in particular, it does what you tell it. In the real world, you tell a dog to sit and anything can happen; in the programming world, you tell a dog to sit and it sits.
(This is why so many of us prefer programming to dealing with the real world.)

*----iOS 7 Programming Fundamentals, p. 33