My boss once asked me (feigning interest), "How do you write a song?"
This happened in the midst of an actual work-related conversation, so needless to say, I was taken by surprise.
So, there was a lot of stuttering and stammering, and I believe I said "you know" approximately 38 times. Meanwhile my boss was thinking, "I was just being polite".
I never did answer the question satisfactorily. And mercifully, we went back to discussing weekly production goals and overtime.
The problem, as I see it, is that songwriting is such a technically challenging vocation that it defies description.
Alas, if I'd only had this video to show her. It truly explains my songwriting process.