You know your exhausted when.....

[Qtrmidad]

When you go upstairs to shave and shower, and that process is usually auto pilot.

You get back downstairs and your wife and daughter ask, did you comb your hair? And you realize you kind of missed that little step!

[ThirdOutOfFive]

When you tell the waitress that your daughter needs a child's menu, and she is 14. That was nearly 20 years ago, and I still hear about it.

[Elle]

You look in and around the coffee maker to find out why your coffee is grey instead of the usual carmel colour (all the while holding a 2 litre carton of skim milk instead of the pint of half and half that you have used every morning for 30 years).

[Elle]

You wonder why your glasses are fogging up when you are wearing them ....in the shower.

[DrPepper00]

The Dr. tells you to get dressed and you say, "Aren't you going to do the exam?" She says, "I just did it." and refers you for a sleep study for short term memory loss.

[kteague]

Your friend calls you for a ride home from her dialysis treatment and knowing she hated to inconvenience me, I thought that before I let her out I should reassure her that I really didn't mind giving her a ride. I looked over to say just that, only to realize I was well on my way toward her home, but I had passed the hospital and never picked her up.

[Kody]

You wonder why your glasses are fogging up when you are wearing them ....in the shower.

Along the same lines, you wake up reaching for your glasses, then realize your still wearing them.

[RocketGirl]

You walk purposefully into a room and stop short, wondering "now what was I looking for and why am I looking here?"

[Sheriff Buford]

You are taking a whiz... and you realize you completely missed the toilet...

[TalonNYC]

You're talking to a client about their tech issue, and realize they've asked you a question, but you have no clue what the question was...

[squid13]

You get out of the car at the WalMart parking lot and start walking towards the store and stop and say to yourself, what am I here to get. You have no idea and turn around and go back to your car and go home and to this day I still have no idea what I went for.

[snuginarug]

You know you're exhausted when not finding a certain pair of shoes makes you cry.

[idamtnboy]

You walk purposefully into a room and stop short, wondering "now what was I looking for and why am I looking here?"

That's when you know you really do believe in the hereafter. "What am I here after?"

[Kairosgrammy]

When you walk out the door to go to work and don't have anything you need. So you go back two and three times trying to get it all together.

When you go upstairs to shave and shower, and that process is usually auto pilot.

You get back downstairs and your wife and daughter ask, did you comb your hair? And you realize you kind of missed that little step!

[chunkyfrog]

You are driving on the highway, pass a mile marker and wonder what happened to the last five.
edit: You have developed a way to take a 5 minute 'power nap' at work while sitting on the 'throne'.