Boundlessly optimistic

I found out today about a "Fatigue Score" that the ambulance service uses to try to make sure that they don't wrap themselves around stobie poles when they are supposed to be unwrapping you from them.  It's a simple three-step process:

1. You get a certain number of points for how many hours of sleep you got in the last 24 hours.
2. You get more points again for how many hours of sleep you got in the 24 hours before that.
3. You get a final chunk of points for the difference between the points you got in the first two steps and how many hours you will have been awake by the time your current shift finishes.
4. You get more points again if you have to keep going back to the start because you're so tired you can't remember how many points you have.
5. You lose points if you notice that this is no longer a three-step process.
6. If you understand the process you automatically score zero.

If you score higher than a certain cutoff you must ring the shift coordinator who will tell you to go home.  Preferably in a taxi.

I was excited about this concept, so I approached one of wise old doctors:

PTR
Can I have a copy of the fatigue score algorithm?

Wise Old Doctor
Sure, here you go.  Why do you want it?

PTR
I reckon I can use this to get out of the 4 a.m. nappy change at home.  I'll just show my score to my wife and go straight back to sleep.

Wise Old Doctor
That's a great idea!  Except no matter how high your fatigue score is, I can guarantee you your wife's will be higher.