Its true. It happened to me as well when i was going to school. I got into the habit of going to bed very late at night (early in the morning) and sleeping through my first couple morning classes. Not good. Unless you actually force yourself to get up early you will never break that pattern. You'll be tired and feel like shit for the first few days but eventually your body will be tired enough that it will have to rest at the proper time.

It helps now that I'm going to work because I more or less am forced to get up in the morning.

IronWorker