But it was funny, because almost everyone else was in the same boat. No one at work seemed to have a lot of energy. People were zapped. Zapped zombies.
I decided on the most obvious explanation. Alien invasion.
Hear me out.
If you were an invading alien force, what day are you going to invade on. A Friday? Bah, people gather energy so they can go out and have a good time on Fridays. Frankly I feel bad for alien invaders who pick Friday. "Ah, this Midwest town will be easily conquered, as they're tired from a week of working!"
But very soon they learn that the only thing Midwesterners have to look forward to is a weekend of drinking. Friday is not a day of rest, it's a day we muster all the strength we can, and we turn our amps up to 11. We go out, stay up later than normal, and we easily defend ourselves from stupid alien invaders.
Monday on the other hand, Monday is the day when people, for the most part, just don't care. If aliens invaded on a Monday, most people wouldn't have the willpower, so early in the week, to fight back. We'd just be angry that we came to work on humanity's last day.
Now, who really knows why Mondays historically suck. But here goes...
MONDAY ALIEN CONSPIRACY THEORY:
Aliens, in conjunction with beer manufacturers, are spending the weekends getting Americans drunk. Beer, liquor, spirits---it's all unearthly. That song "Shots" by LMFAO featuring Lil Jon is a construct of the invading alien force. Let's be honest, Lil Jon is a fucking alien.
Also, that girl/guy you went home with? Just a ploy by the aliens to deplete your energy and make you feel bad about yourself, depressed, and thereby vulnerable to attack.
Come Monday, we're struggling. We're hung over. Our energy stores are depleted. On Monday, Earth's wallet is empty, Earth's mouth is dry, and Earth's belly is full of debilitating McDonald's drive-thru. Leaving itself open to an easy and successful alien invasion.
Trust me, it makes sense.