So you're a kid, and your decrepit Great Aunt shows up in her nearly purple hair and a massive floral-print dress. As her support hose bunches around her ankles like the wrinkly legs of an elephant and she complains about another bout with the rheumatism, she'll arch her crackly back, lean forward to plant a kiss on your chubby, scared shitless cheek, and spread her massive maw, painted in classic Whore Red, to reveal quite the same shade smeared across her dentures as though this morning she had opted to have lipstick for breakfast rather than simply apply it as is customary.
What you may not have known at the time is that Granny Red Tooth wasn't necessarily insane or trying to start a new fashion trend, but is instead suffering from any number of neurological disorders characterized by shakes and spasms making it remarkably difficult for her to manage the application of that insanely inappropriate shade near her choppers.
According to research, over 10 percent of people over 65 suffer some manner of shaking. That means tasks as simple as the application of make up, eating with a fork or even throwing a ninja star accurately can be more of a chore than you'd think.
Combine that with eyesight problems beyond what can be fixed with a simple pair of old lady glasses, and it's easy to imagine how you can leave the bathroom looking like a bizarre combination of the Joker, and someone who just ate the Joker.
You may have noticed that grandpa always had a pocketful of butterscotch candy. No, it wasn't so he could entice bag boys at the local supermarket to reach into his pants. Indeed, there's a reason the vast, slow moving, creaky army of elderly people insist on keeping that massive lead crystal bowl of ribbon candy until it has melded into one giant, sugary art installation on the coffee table.
As you age, the sense of smell and taste tend to fall by the wayside, giving up on your rickety frame and jumping ship before they go down with you. Smell goes much more quickly than taste, but since the two are so closely linked, and by virtue of the fact that smells interact with receptor cells to help you fully understand the actual taste of what you just ate, when they leave you all you have left is a basic understanding of the taste of sweet, salty, sour and bitter.
Elderly people tend to choose sweet as the taste of choice, since it's the most pleasant, and also because scientific evidence indicates old people with pants full of salt licks are often assaulted by deer and left confused and disheveled at local malls.
It's interesting to note that old people driving skills bare a striking resemblance to objects approaching the speed of light. Physics tells us that the closer you get to the speed of light, the slower time goes until, presumably, time would hit a dead stop. Likewise, the older people get, the closer their driving speed gets to being slow as shit. We can theorize that the oldest human in the world, if placed behind the wheel of a car, would somehow be able to burn an entire tank of gas whilst going absolutely nowhere.
This sad state of affairs is actually caused by a delightful stew of decrepitude faced by all of us as we age. From the top down, elderly drivers get to experience a variety of ills like glaucoma and macular degeneration which cause eyesight to degrade; thus limiting their ability to gauge what's coming on the road ahead. Hearing loss further kicks you in your old guy crotch by taking out another sense necessary for drivers to be fully aware of what's going on.
Ignoring the road would be dangerous if they were actually moving.
But worst of all, the rest of the human body follows suit. Age takes its toll on the muscles and nervous system, causing a lack of flexibility and slower reaction times. Knowing your reactions are slower makes it seem like the outside world is going terrifyingly fast.
Thus your grandfather is now deathly afraid to go above 30 mph, knowing he can't see or hear what's ahead or behind him and can't get out of the way fast enough even if he could.
So when you're late for work and get stuck behind one of these guys, and swear out loud that you'll never be a slow driving, high pants-wearing, hard candy-sucking Yoda, just remember: at your age, that's what they said, too.
"I'm you! From the fuuuture!"
For more rational explanations for irrational behavior check out 5 Douchebag Behaviors Explained by Science. Or find out about what scientists have to say about your junk in 6 Sex Myths as Explained by Science.
And visit the Cracked.com Top Picks before you get too old and crotchety to care.