Old Folk and the Slow Driving Syndrome

I've recently been pondering the phenomenon known as "Why do old people drive so freaking slow?". Why do they do this? Do they realize what they're doing? It captivated my imagination so much that I decided to dedicate three hours of my life investigating this.
Like any good scientist, I made my hypothesis...I came up with 4 possible conclusions to the elusive question.
The first possible answer is that the lack of bone density that occurs with old age causes the ankle bones to become crisp and brittle, thus making it too difficult to apply the required amount of pressure on the gas peddle.
My next idea was...maybe retirees are so bored that they get great entertainment from the scenery. They simply "stop and smell the roses" while they're driving. Maybe they drive slow, because they have the time, because they can.
The third answer...It could be a generational thing. In their day, everybody drove land yachts in a cumbersome fashion. Maybe in the year 2050, the speed limit of 80 mph will seem outrageous to us. It could be the same thing for seniors now.
The last possible answer... Brain deterioration.

During my four hour investigation I drove around observing old people, I got 99 cent crispy chicken nuggets, I went to the rich catholic park. Then I tried desperately to find a single common characteristic between all the elderly. Besides the fact that they all drive Buick Century's I noticed that old men drive significantly slower than old women. I don't know why that is and I don't care. I learned nothing.

A couple days later I was driving home from Will's house, it was about two in the morning and I was far more tired than I commonly am. I noticed that everything seemed as if it was moving fast, then I looked down and noticed I was only going 45 mph, eeh gads! But it seemed soooo fast! I couldn't go any faster! too. much. speed. Then it hit me, the answer is fatigue! One of the common symptoms of old age is constant fatigue! "oooh I have to take a nap" "ooooh I just woke up, but I'm soooo tired" "all I did was go to the fridge, soooo tired!" "I did soooo much today, I got the mail, ate lunch and napped, I'm soooo tired!".
So there is your answer, senior citizens are simply too tired to drive fast.
What's the solution you ask!? You're sick risking my life trying to pass them all the time?
The answer is also simple. They need to STOP WAKING UP SO EARLY!!! STOP IT!
"Early to bed, early to rise, makes a man slowly, slowly drive" ~Benjamin Franklin