Surely every writer merely sits before their workspace and lets the ideas pour in like lemon aid from a pitcher. The paper is the glass and the words the lemony sweet liquid we so thirstily gulp down.
If there is one thing I have learned it is that this is not always the case. A writer is constantly thinking. They comb the world before them for inspiration even after they have stepped away from the desk.
We must go out and find our idea wells. Our "concept reservoir" that provides us with our richest, strongest plots. Without new sights and sounds, the well would run dry. The writer who stays only at their desk will surely suffer a drought eventually.
I don't think a writer becomes such the same way a plumber or programmer takes up their trades. I think that to become a true writer, at least a fiction writer, you have to live the career. Your mind becomes a machine, extracting all the world presents then pushing it through the refining cogs of perception and emotion. Sometimes many parts must be pushed through for a coherent idea to emerge.
So where does this happen? Everywhere and anywhere. If there is motivation there will be a writer with a revelation.
Oddly enough I have found that the shower seems to be my thinking ground. I can not explain why. Is it the primal nakedness? The cleansing water washing down? Is it the tomb-like walls that surround as barriers from the world, allowing my mind to flourish? Maybe it is the pure lack of distraction?
Whatever it is, I have had some of my strongest concepts hit me as I bathed.
However there is a process here. I can feel the thoughts budding, a flash of an image that reappears consistently in my mind. Or the hint of a word or sentence that builds on itself.
I suppose the lesson I am taking away from this is always have a pen handy for when those overpowering ideas hit. Also, take many showers, because idea's seem to love the water!