He does not like change!!

I watch Zach's teacher's kids during the school days. She dropped her kids off today later because she had a district panel she was asked to be on. When Zach found out she would not be in class today, he was mad. He went to his room and closed the door. I told him that it was not the teachers fault, she was asked to be on the panel. So, when she dropped the kids off, I told her Zach was not happy she was going to be gone again. She felt so bad....she had already missed 3 days this month because of being sick, being out of town and being at another district meeting. She is a fabulous teacher, the most requested at the school. Anyhow, she said she was reading in Zach's school journal (the students write in a journal back and forth with the teacher, they can ask the teacher questions or just tell her their thoughts.) On with the story, Zach had wrote how bored he was....for two days her told her how bored he was. She said she felt so bad. She really tries to keep the kids motivated and constantly busy. When she looked to see what days he had wrote these comments, they were on the two days she was gone, Friday and Monday. Zach does not like change in his schedule. He likes to know that everything will go as planned and there should be no hitches. He wants to know when it is happening and for how long. Zach likes to know what time company is coming three weeks from now and how long they plan on staying. He does not want them to go, he just wants to get it in his schedule.
I HAVE NO CLUE WHERE HE GETS IT FROM!!!!!!!!