Ds walks to school every day. This week is Walk to School Week, and every child who walks to school every day this week will recieve a reward onFriday. But this week ds has an appointment, which means that he will arrive by car tomorrow.
So ds, who normally walks to and from school every day, gets no reward. The kids who normally drive to school every day will get a reward for only driving home.
I didn't say anything about this to ds. But he's no fool, he worked it out for himself, and he is Not Pleased.