I have the feeling you are one of those guys full of energy at 6:00 AM who drives everyone nuts but then by 2:30 you are gassed and checked out at work.
I hate dealing with those guys. They get to work at 6, sit around doing nothing until 9 because no one else is there or responding to emails, and then they hit lunch at 10:30 right as the rest of the team is getting rolling. Then after lunch they refuse to start anything new because they are headed home at 2:30. Rinse and repeat the next day. Yup, seen that many times.