There is a pattern.

We all have a set of activities we do in a daily basis, we all have routines. So there will be something that we do where most of your ideas come from. In this case the pattern is that I (for example) wash the dishes and get an idea, something 'clicks' in my brain.

So:

1. You do mundane stuff
2. It frees your mind and you get creative

You find something you can get lost in, something you don't have to concentrate on.

I am just going to write done some random tasks I do and what is happening in my brain while I do them, just going to look at what my brain is doing while I complete those tasks. Not the ideas come up with. In sort of what state my brain is, like say the messenger stats: busy, away, be right back, in a call, available, out to lunch and appear offline.