Are All Programmers Crazy?

I see programmers everyday,
Working alone in their computers,
Talking to themselves while typing,
As if waiting for the monitor to reply.

Why do they tend to do that?
Is it because speaking makes the process flow easier to understand?
Or they have no one else to talk to, because everybody is busy with their own tasks?

My point here is this:
If ever we see programmers talk without speaking to any one,
I suggest that we should not disturb them,
Because we may never know,
They may get distracted and lose their momentum with what their thinking,
And we may never know,
That their craziness is the key to have a more accurate logic formulation, a bug-free code, and an exception-free program.