Do I have a sleeping disorder?

Or am I just a typical night owl? It is currently 1:30AM and I’ve been laying in bed for the last hour, unable to sleep. I don’t feel tired. I actually feel quite alert still. In fact, I could probably stay up most nights and still feel this way until well after midnight. If I exercise or do something physically active in the afternoon or evening I don’t feel tired until about 2:00AM or so. I sleep like a log when I do fall asleep. I can easily sleep through trains, alarms or children crying. Any advice?