"Sick Days"

Why do sick days always end up coming on days off? It's really not fair. My little (I suppose that I can't call him little anymore, since he's over 6 feet tall, and 17 years old now....) boy is sick today. He came down with a fever last night (alas, not until he had to go to church....the illness truly struck after he came home...another injustice?), and has been in bed for the last 13 hours. He's not even enjoying his sleep. And, true to my word, I made them do all of the chores they had to do on Saturday, so that they could enjoy today! Now, he's stuck enjoying it in bed....SICK. If today was a regular school day, chances are that he would have awoke this morning feeling fine.
On a good note, I don't have school today, and I only have one class tomorrow! I have my homework done, and I really don't have much studying to do for today! I think that I will enjoy my day off! :)