To pass this week's challenge, you have to at least plan a day of nothing but fun for your son.
It's good to be focused and goal-oriented. I love looking back on a day and recalling all of the tasks that I accomplished that day. It's easy to get caught up in cycle of work and goals and entirely miss out on the fun and spontaneity of life.
Pick a day, preferably in the middle of the week, and call in sick to work and spring your kid from school. Then go see a movie and go bowling, drive go-karts, do fun stuff just because it's fun. Enjoy it.