This is about the feeling of calm you can get when gently and rhythmically your nicely laden paint brush strokes a piece of wood. You are alert and your eyes are looking carefully, controlling your movement, making sure you are accurate. In the background a radio plays music, which you are aware of in a different part of your brain. For a short time nothing else exists.
This feeling only really happens when you have a small job that is not going to take too long, where there is not the pressure of productivity and having to finish to a deadline – in other words a little bit of hobby diy, not work.