You know you're up too late when...
Believe me I know EXACTLY when it's too late, or more to the point that I've stayed up for too long consecutively (sometimes numbering in days, not hours)...
1. You're eating breakfast while still having on the same shirt you ate dinner in.
2. You've seen the weather change twice or more.
3. You're too tired to drink but too awake to go to sleep.
4. The taste of bacon will not leave your mouth.
5. Your US friends you've been talking to online are going to bed and your UK friends are waking up and start talking to you or vice versa.
6. You have two consecutive one night stands. Normal day of work, then bar at night, sex, then after the sex get up and clean the kitchen, cook them breakfast, both go to work, lunch, more work, then evening bar trip again, one night stand with same or different chick, then if you're awake after that, every second thereafter you are awake WAAAaaaay too long. Extra if you were in different towns or at your house one night and theirs the next or vice versa. Yes this has happened to me. No I don't want to do it again.