|This picture pretty well describes my mood most mornings.|
In my unofficial, unscientific research on the subject (having one child who is a morning person and one child who is a night owl), morning people seem to be overly enthusiastic in the morning, and night owls appear to be mildly irritated by that enthusiasm.
Thanks for reading-- Max Wachtel, Ph.D.
Biss, R. K., & Hasher, L. (2012). Happy As A Lark: Morning-Type Younger and Older Adults Are Higher In Positive Affect, Emotion, 12(3), 437-441.