Is it just me?

Why is it happening? Today, as per usual, we wake Ezra up and get him ready for school. He seems unusually quiet on the journey and did not even touch his breakfast. Upon reaching the school, he requested to go home and start to cry a little. *sighs* Why? It seems that every time I bring him to school he will cry. Even though he knows that I will be back to pick him up, he just refuse to let me go. I know that he can't bear to be separated with me even for that brief 2 hours. But I really wonder how can I help him to be more confident.