Q: How do you know where to start [writing]?
A: It usually just pops in my head and rams itself into the sides of my dura mater until I bleed it out onto paper or word processing.
That sounds painful.
Exactly! That is the life of a writer!
Ouch... is it worth it?
God dang, yes it is. Agonizing over words and typing until you develop Carpal Tunnel and arthritis is the best feeling in the world.