We all have different type of nature to what our body is adapt to, it might make you feel comfortable while awake at night or your body system will just be as normal adaption to never cheat nature which Is finding a nice time to sleep at night and the best way to notice this is to discover yourself.
it just so happens that many of us prefer the wee hours of night... when our mind gets a little bit of peace and even though our whole being screams out to rest like the good little angel on one shoulder, the devil on the other shoulder says "stay up just for 10 minutes" and that 10 minutes become 2 hours and so on