Recently had parents evening at school. My DS is doing well generally, but his teacher said he is a bright boy and is capable of doing much more if he would try harder. Apparently he is happy to "coast" along. She said some days he is excellent at concentrating and he has made massive improvements in his writing and reading and has even recently won the school award for a piece of writing. His teacher says that the problem is that somedays he comes to school like a different child - just doesn't listen, is very defiant and even sometimes rude 
. (He can be quite cheeky to me at home, which is something that me and DH are working on.)
The teacher questioned me about bed times and what he has for breakfast. He is in bed WITHOUT FAIL at 7pm and only has wholewheat cereal for breakfast (usually porridge).
I really can't think what is causing these disruptive days in him??
Or is it just his age?? He is my eldest, so no other child to compare him to.
TIA