I must have spent the equivalent of days and even months of my life thinking about things that make my head hurt.

For example, how do gasoline stations get the price to come out to the penny when they tack on nine-tenths of a cent onto the cost of each gallon?

I realize that they just round up the .9 cent to the next cent, which earns them more money and lets customers think they're getting a bargain. After all, $3.679 sounds much better than $3.68 per gallon.

However, this seemingly random thought did give me an idea as I approach my 59th birthday this week - appropriately on Friday the 13th.

Why don't I just keep my age at 58.9? The government and other official-type agencies could just round it up, but still leaves me feeling that I'm 58.

This method would definitely be a big plus next September when I am destined to reach one of those "big-whatever-Oh" birthdays.

My old friend Professor Van Von Venn is the world's foremost authority on useless information, so I turned to him for further insights on that subject. (I must be getting old!)

"The first two decades of our lives pass relatively quietly," said Von Venn. "Sure, there might be a little fuss on the 10th birthday when little Cornelius or Cornelia hits double digits on his or her birthday cake candles. But it's no big deal.

"The birthday that kids look forward to eagerly and parents warily is the 13th, the one that catapults kids into teenagers.

"Likewise, 20 does not rate the 'big 2-Oh' designation because it is bracketed between much more important birthdays.

"The first comes when the teen turns 16, clearing the way for driver's permit and eventually driver's license for the teen, and sky-high insurance premiums and gray hair for the teen's parents.

"Turning 18 is a semi-big deal because that is the legal voting age, but given the choice of candidates, it almost makes a young person want to stay 17 indefinitely.

"Of course, just on the other side of 20 is the legal drinking age of 21. However, this novelty fades for many people who discover it is much more difficult to make a fool of yourself while sober."

I was about to note that the professor does a very good job of doing that, but Von Venn kept right on talking and proving my point.

"The age 30 is the first birthday that gets 'big-Oh' status," said the professor. "When we are young, people 30 and older seem ancient to us, so we assume that be the beginning of our descent into decrepitude.

"However, we awaken that birthday to find that we are just as youthful as ever and immediately begin to think that the next 'big-Oh' birthday at 40 will change us dramatically.

"I must admit that 40 is a bit scarier because it also marks the approach of middle age, that undetermined point midway between being a whippersnapper and an old fuddy-duddy.

"It's about that time that most people realize that they are most likely not going to realize their childhood dreams of playing in the NFL, dancing a lead role in the ballet "Swan Lake," or painting the ceiling of a church or chapel, or even painting their minister's car.

"In most cases, the big 5-Oh is not as traumatic as 30 and 40 were. Some people do get a bit panicky when they think that they have been on the planet for a half-century. Somehow, they have always thought of historical figures like Washington and Lincoln in terms of centuries, and not themselves.

"The majority of people sail through 50 without much difficulty. They realize that life is a series of adjustments.

"If they can't do something the way they used to, they can do it another way. If they still can't do it, it probably doesn't need to be done.

"Besides, they look on the bright side and realize the older they get, the more of a medical education they get as they try to keep up with what is next to go wrong with them."

Pausing for full effect, Professor Von Venn looked at me before discussing the fate that awaits me in little over a year.

"The 'big 6-Oh' is usually the last of the milestone birthdays that get 'big-Oh' status. When people turn 30, they automatically think that they will not consider themselves old until they reach 60.

"However, when that age arrives, it suddenly doesn't look that old and neither do the birthday celebrants. They really don't know what being 60 should feel like, but they certainly don't feel like that.

"After that, the decade birthdays are a breeze. Once you hit 70, 80 or 90, everybody starts to tell you are 70, 80 or 90 years young. If you can manage not to look in a mirror too often, you may even feel fairly young."

This lecture had me feeling relatively good about my approaching birthday until the professor reminded me the day I was born was my original birthday, so my 59th birthday is actually my 60th.

Let's just leave it at 59.9 and call it even.

(Walt Kozlowski, a freelance writer from Mount Carmel, composes "Walt's Way" for each Sunday edition.)