“Oh, sir, your grandson is absolutely adorable!” “Well, thank you. But he’s my son.” “Oh, I ... I ... I’m sorry; I didn’t ... ” “Don’t worry about it – happens all the time.”

Such is the conversation once a month or so as I, a 58-year-old male with a white-speckled beard, and my 6-year-old travel to stores, to schools, to activities across southern Wisconsin.

Now, this error in paternal identity is not nearly as dumb as was the time I asked the woman at the park if she was pregnant – when she wasn’t.

But, despite the fact I’m about as sensitive to “granddad” quips as an old mountain boulder, most sheepishly recognize the faux pas and spend the rest of the uncomfortable conversation trying to pull their foot out of their mouth as they gracelessly move on.

Dads who look like granddads – another situation for this world to deal with.

Since you’re readin’ this, I can also explain the whos, the whats, the whens and the wheres behind my recent donning of the silver “Grand Dad” cape and tights in the first place, which is the very seed of this story.

I divorced about 12 years ago – who hasn’t been, right? Now, those particular whos, whats, whens and wheres – thankfully – are not important right now.

But what is noteworthy is from that relationship sprung two fantastic kids: Jonathon, 24, who is a recent college graduate; and Sarah, who my ex and I adopted when this still-little girl was just 3 months old.

When they were young and I was young, too – without a single gray hair on my whole body – we also traveled to stores, to schools, to activities at a little quicker pace than I do today.

With books and pen in hand, I proctored every practice, every performance, everything.

Friends, relatives and acquaintances in our small town looked at me as an honorable, hard-working teacher, which is my day job, deserving of their thanks and respect – items not given so easily in this new, unfortunate day and age.

As well, our town perceived the four of us as a stable, nurturing, model family unit.

And we were.

But I also found my new path. My master’s degree, theater, teaching and writing dominated my personal and professional development as I strived to be somebody – or so I thought.

As the whole universe knows, measurable and worldly achievement comes only with time, work and sacrifice – and sacrifice I did.

So, because God created only 24 hours in a day, I did see Jon and Sarah each and every day, but I didn’t watch them, study them, examine them as one really should with the genesis of rare, beautiful flowers.

I was as good as any father my age – but not nearly as good as I could’ve been or as I am now.

So what happened in the first marriage? A dozen years after the divorce, I’m still not sure.

What I do know is that everyone else seemed to know the answer: I was too dedicated professionally; I possessed too much mid-life crisis; I displayed too much selfishness, too much this, too much that – and so on, as has been and will repeatedly be spoken by humankind since the dawn to the end of time.

But, after years of my two kids keeping my ex and I together, for their benefit – despite the months and months of pain, agony and tears before and after the decision – we separated.

I still weep today when I think of how I wept those first few months away from Jon and Sarah three to four nights a week while I found myself purposely alone in a purposely darkened room wondering what the heck happened.

I tried to fill the kidless hours with my master’s degree, theater, teaching and writing, but ironically, they didn’t really help at all.

At 46 and then divorced, I felt ... older. My body felt sore. My head felt bruised. My joints felt arthritic.

My hair turned gray.

But just when I believed that there was no God at all, He saved me for the second time in my life.

A widowed, childless 30-year-old elementary school teacher – who had also learned a lesson or two about life and for some reason seemed to like gray hair – carefully wandered into my existence.

Life’s so strange, so unpredictable, isn’t it?

I’ll let you readers paint the details, but after we met, we dated, we befriended, we questioned, we loved, we promised, we eventually married. And though I thought that Jon and Sarah were enough for me, their new stepmom had a desire to have a child – just one sweet, beautiful child of her own.

So, after a couple of early miscarriages, we were blessed with a 6-pound, 13-ounce baby boy who – interestingly enough – was named after the maternal and paternal granddads he had already: “Vincent William.”

Believe me – the differences in a man when he’s in the parental “it” in his mid-30s compared to one who gets a second chance to be in “it” in his mid-50s are shocking, yet satisfying, simultaneously.

Yes, the first time around with Jon and Sarah, I learned to diaper-change effectively, to burp regularly, to hold lovingly and all the other practical expertise needed.

But this time with Vinny, with my master’s completed, my theater over, my teaching honed, my writing bloomed, I was both blessed to receive the determined, God-given mindset of being the best dad I could be – whatever that took.

Five years later, I’ve learned the “whatever that took” and, this second time around, it’s now simple for this old, hoary head of mine to figure – time, self-control, role-modeling and love.

These concepts were hardly more than just words to me more than 20 years ago. But this second chance at love granted me a second chance at fatherhood – real, selfless, adoring fatherhood.

So where do Jon and Sarah Churchwell fit into all this? Quite nicely, thank you very much. We, they, he, she, all play in fluctuating combinations. Together, Jon and Sarah learn firsthand how to parent first-time.

I sometimes wonder, deep down in their individual heart of hearts, if both or either possess any envy or hard feelings; they never let on such, but it would only be human to feel such.

During family times when Vinny is off grabbing another set of toys, I look at Jon and Sarah with tears in my heart and wish I could’ve known then what I do now. My eyes say that I’m sorry for the past and that I’m sorry for what I sacrificed and that I’m sorry for the agony.

Sometimes, my ol’ ticker can hardly stand it. But then, right before Vinny brings in the next truckload of playthings, they’ll stare right back at me and – just with that look – relate that they love me and everything’s cool.

In fact, Jon – who had just earned his communication and theater degrees, showed off a portion of his $70,000 worth of education by verbalizing specifically, “Dad, I think you’re grand,” just as Vinny came within earshot.

Please, let me make this perfectly clear: At 58, I don’t use Depends, don’t need Viagra, don’t walk with a stoop. But I do take Geritol, force down thyroid pills and put in my hearing aid whenever a social event arises.

Such was the case last week. Vinny, today a kindergartner, was invited to a classmate’s birthday bowling party. So, as I dropped my little man off at the bowling alley just like a dozen or so other parents, the moms and dads of the other kids are 25, 30 years old tops ... and then, of course, there’s me.

After meeting parents, dropping off gifts and comparing my gray hair to their blonde, brown or purple, I was just about to leave when I hear another kid ask, “Vinny, is that your granddaddy?”

Vinny, who is as sharp as a tack just like his mommy, responds with, “No; like Jonny says, he’s just grand.”

Thank you, God.

Happy Father’s Day 2013 to all dairy dads or “grand dads” out there.