How tired is too tired?

When you fall asleep while eating and you do a face plant into your unfinished meal? When you are sitting on the toilet and you doze off without flushing?

Although I can't claim to have experienced these things, I can say I've witnessed them. In person. Really.

So I thought about it a bit. Especially at 2:40 in the morning. I can tell I'm tired. In fact I'm passed being just tired. I'm almost delirious. But am I too tired? For what? I already successfully ate. I didn't fall in. Flushing did occur, although not without some assitance.

So what is next? Do I just fall over in a stupor while trying to type these last few words?
I feel certain that would be a new low, even for me.

*thunk*