1. Having a bad night's sleep.
2. Stress.
3. Waking up earlier than you need to.
4. Bad weather.
5. Waking up but still feeling tired.
6. Not wanting to go to work.
7. Knowing you have a busy or tough day ahead.
8. Thinking it's Friday but realizing it's not.
9. Sleeping through your alarm.
10. A bad commute to work.