If you're under 40 years old, click the back button on your browser. Turn around and walk away. DO NOT, I repeat, DO NOT read this piece under any circumstances!

Okay, you've been warned. I just don't want my 20-something, 30-something friends to get depressed. Especially those of you who may be 39 and three-quarters years old or something close to that.

You see, when I hit 40 I felt like a car with an expired warranty. Everything (and I do mean, EVERYTHING) started falling apart.

I should know about cars with expired warranties. My first and so far only new car ever was great. It lasted me many years. It came off the lot with new tires, as all new cars do.

The tires had their own warranty, separate of the car's. The warranty was, ahem, "backed" by the tire manufacturer. I won't tell you who made the car or the tires.

I will tell you the tires had a 50,000-mile warranty on them. And I swear to you, the minute those tires hit the 50,000-mile mark, they didn't just go flat, the tread didn't just wear out on them, nothing like that. Oh, no.

Each tire, one at a time, DISINTEGRATED while I was driving on the highway. The rubber treads just crumbled apart. I felt as though I was suddenly driving on a rough patch of pavement and when I looked through the rear view mirror I could see little bits of tire flying up from the rear end of my car.

This happened three more times. And it's how I felt after turning 40 years old a few years ago.

The tires were past warranty so there was nothing I could do other than to buy new tires--a different brand of course. As for me, I come with no warranty so my poor wife is stuck. "Till death do us part" or something (and no, divorce is not an option--oh, hi honey!).

The first things I started to notice were subtle. Reduced flexibility (not that I've ever been flexible my entire life), more aches and pains, worse memory (and my memory was always bad to begin with), feeling tired all the time.

I was never one to go to doctors before--I practically had to be bleeding gallons to allow myself to be dragged to one--but I became an instant hypochondriac.

It started with my IBS (irritable bowel syndrome), or at least my belief I had IBS even though I had never officially been diagnosed as having this condition.

I went to see a gastroenterologist. He was a young resident but he was meticulous and cautious. He ordered a colonoscopy and an endoscopy for my esophagus and stomach.

In short, I was going to get it from both ends. Literally.

I underwent both procedures on the same day, under (very) heavy sedation. They also shoved an electronic capsule down my throat and I was to carry around a small beeper-like device for a couple of days to record measurements of my gastrointestinal acidity taken by the capsule.

After everything was said and done, the doctor did indeed diagnose me with IBS. He also found I had acid reflux--officially, gastroesophageal reflux disease, or GERD--even though heartburn was not a major issue for me to that point.

Great, I thought sarcastically, another wonderful aspect to getting old.

The next medical issue I tackled involved my sleeping and snoring. I was told I snored very heavily--in fact, this had been going on since my late teens and early twenties, when I was in the Army and my barracks roommates constantly ragged on me for my snoring.

My father had had the same problem and it turned out he had sleep apnea, which is a condition where your airway is blocked or partially blocked by soft tissues (this is what causes the snoring) as you sleep. Once he got treated for it, which involved sleeping with a special machine that helped you breath, he said he felt much better and more rested.

So I went to have a sleep study done and lo and behold, I was diagnosed with sleep apnea too. That meant I'd have to sleep with a CPAP (continuous positive airway pressure) machine, which sent pressurized air up my nose through a rubber hose and kept me from snoring. The "mask" I wore to breathe at night with the CPAP looked like a cross between the headgear worn by college wrestlers and the monster from the movie Alien when it attached itself to its hosts' faces. Needless to say, I didn't have much of a love life.

But at least I was sleeping better now, if alone.

About this time I got on a health kick and decided to start working out and eating healthy. I lost weight, put on muscle and started looking and feeling better until I hurt my lower back while working out.

I had had lower back problems since I was in high school, mostly associated to my weight (I was always "the fat kid" in school). Oddly enough, or perhaps because I was in great shape then, my lower back was never an issue during my four years in the Army. I suppose I was lucky in one sense: my lower back problems were muscular in nature; in other words, they weren't caused by a pinched nerve or a problem with my spinal column.

Doesn't mean my lower back hurt any less, though.

I lived with the pain a few months and eventually regained all the weight I had lost, and lost all the muscle I had gained.

Then there were my allergies. Or so I thought they were allergies.

I went to an allergy specialist who couldn't find anything I was allergic to. My official diagnosis was non-allergic rhinitis.

That didn't explain my constant sneezing--so much so that at the cube farm where I worked, my co-workers had a betting pool going to see who could guess how many consecutive times I'd sneeze when I got into one of my numerous daily sneezing fits.

The allergy doctor gave me some medications and nasal sprays which helped but weren't perfect. It seemed as though I would just have to live with my non-allergy allergies, just as I had to live with back pain, heartburn, IBS and an awful mask so I could sleep.

Okay, you twenty-somethings and thirty-somethings who didn't listen to me earlier when I told you to quit reading? I have some advice for you:

Whatever you do, don't grow old. The warranty sucks.