There is a specific and intense joy of belonging to the task that one is doing. Probably there is no other way to enjoy any task than knowing that nothing more is important at this moment to do.
Often times our joys are sucked out by parallel tasks running in our mind. I’m dropping my brother off but I‘d rather have spent a slow early morning in bed. I’m sitting here writing a story but that e-mail is more important to be sent. I’m spending my afternoons cooking, instead of giving that extra bit of time my work needs me on. So on and so forth. Recipes of deep unhappiness.
This is the reason slotting of time matters the most. Knowing that nothing else needs priority than the task at hand. Knowing that everything has been given its due share of time. This is what allows for tasks to be fun, this is what allows for flow to happen! Your hourly calendar is a tool that can bring sustained joy!