The three most productive locations for solving complicated long form thought problems are sleep, shower, and shitter. In reverse order.

All three have the commonality that, traditionally, you’re not disturbed and you can think at a relaxed pace.

I'd add bike to that list.

I should bill for my shower time. It's usually the most productive part of the day. After that I know exactly what code I need to write and how I'm going to tackle it.

On the other hand, I miss taking showers without muttering to myself.