It used to be, you said “Five-0” to me, I thought “Hawaii,” as in “Hawaii Five-0.” You know, McGarrett. Wo Fat. And “Book ‘em, Danno.”

But now when I hear “Five-O,” I think, “Oh, yeah, I’m Five-O, as in 50-years-old and counting.”

Now, for the record, it didn’t bother me to hurdle this chronological milestone. I’ve always lived by the words I heard years ago (and unfortunately I can’t remember the author … or much of anything lately) that old age is defined as 15 years older than you are. When I was 18, I was told not to trust anyone over 30. When I hit 30, 45 seemed to me to be the height of maturity. And at 45, I considered 60 as “getting up in years.”

So hitting 50 didn’t smack me for its significance as half a century as much as it meant I still have at least 15 years before I can ponder retirement.

Now, I appreciate that to that long list of “two kinds of people in the world” (i.e., cat lovers versus dog lovers or Pepsi drinkers vs. those who prefer Coke), you can add those who like a fuss made over their birthdays and those of us who do not.

When it comes to reacting to birthdays, I have been consistently and boringly neutral ever since my mom explained that I had outgrown having a kids’ party. Since then, I neither see them as a cause of celebration, nor consider them as a time to pause and imagine the Grim Reaper pulling out his Palm Pilot to double check when exactly he’s suppose to pay me “the visit.”

Nor have I ever had a midlife crisis, mainly because my wife told me I couldn’t. A friend of mine had one. He traded in his wife for a newer model, changed his hairstyle and took a new job where he gets to travel more. If I did have one, it probably occurred one weekend when I felt the urge to listen to NPR and begin appreciating the finer things in life. But this lasted only until I stumbled on a “Dukes of Hazzard” marathon while channel surfing.

So there I was, content to watch my fiftieth birthday come and go. Then it happened. Two days into my fifty-first year, I went to the mailbox, and there it was: An invitation to join AARP, along with a temporary membership card. I now had something tangible in my hand that I had, indeed, hit a milestone. I could feel my hairline recede and my hearing fade. I stepped into the living room, but I couldn’t remember where I was going, or why. My knees began to ache, and I was torn between a desire to watch the Weather Channel or just take a nap.

See, the way I figured it, AARP was always the last club you joined. Soon after, I imagine they starting sending their newsletters printed with extra big type and emails asking you call your congressman about Social Security legislation.

Suddenly I have this urge to turn the TV up loud enough for everyone on the block to hear, hike up my belt well past my belly button, and yell at the neighborhood kids for running across my lawn. Now, if you’ll excuse me, I think I’ll go enjoy some warm applesauce while I listen to the “Music of Your Life” station on the old Victrola. Hey, did you know David Bowie turned 58 this year? “Ch-ch-ch-ch-changes ….”