The human mind

Because much human behavior is subconscious – that is, it occurs without conscious awareness – we often don’t know what we are about to do, say or think until after we have done it. It’s as if we had two minds: the subconscious and the conscious, which don’t always talk to each other. Not what you’ve been taught? True, nonetheless. More and more evidence is accumulating that we use logic and reason after the fact, to justify our decisions to ourselves (to our conscious minds) and to others. Bizarre? Yes, but don’t protest: enjoy it.

– Don Norman, The Design of Everyday Things