As a fan of the British documentary film series UP!, I’m inclined to accept the basic premise of the quote on which the films are based: “Give me the child until age seven and I will give you the man.”

The origin of the line may be obscure. But, the case for its veracity strikes me as pretty solid.

Maybe that’s why I love convertibles. There’s no denying that long before I hit the seven-year mark, I’d accumulated enough first hand experience with these magical metal chariots to leave a permanent imprint on my all-too-malleable young brain.

Although I’ll probably never know what, if any, developmental mischief was percolating in my noggin back in those halcyon days, the fact remains that I’m a sucker for a ragtop. Not just any ragtop either, mind you.

Fortunately, early childhood exposed me to a fine selection of genuine classics from another “British Invasion” immediately preceding the musical one led by the Beatles and the Rolling Stones.

Come to think of it, the one I’m referring to also featured a talented, entertaining line-up of charismatic Brits. They came in the years following the end of Word War II with names like Jaguar, Triumph and MG emblazoned in chrome script across their fenders.

Upon arrival they proceeded to attack America’s winding back roads with a vengeance, preaching the gospel of “motoring,” a brand-new form of four-wheeled, outdoor summer sport.

The typically quirky Brit term for a cloth-topped sports car of this era is “drop head coupe,” a colorful phrase that never caught on with Americans. On this side of the pond, we called these tiny topless two-seaters “roadsters.”

When I was barely old enough to walk across town alone and shoot aggies on the school playground, my older sisters were zipping around in some of the sharpest examples on the planet, including such automotive icons as the 1953 MG TD and the sensuous XK120 Jaguar.

I was only six when my sister Liza gave me my first ride in her diminutive MG roadster. Actually, given that car’s cramped interior, my youth provided an ergonomic advantage in that I could slide into the cockpit without folding myself up like a jackknife.

That first ride was pure magic. I’d just settled into the leather-clad bucket seat (it really did resemble a bucket with the front lopped off) and was admiring the genuine wood dash with its simple, purposeful array of gauges, when my sister fired up the engine.

The sound proceeding from beneath the “bonnet” and rippling across the warm summer evening was glorious. The Brits (of course) have a word for that sound, too. The symphony generated by a proper British roadster is always “rorty,” which my New Oxford American Dictionary defines as boisterous and high spirited.

Actually, that pretty much describes the whole magical experience of my first roadster ride.

Have you ever had a dream of flying? It was like that, only more so.

The symphonic blend of mechanical sounds, the warm breeze swirling around us, the blur of passing scenery, the intoxicating olfactory cocktail: pine trees, salt sea air, sun-warmed leather and partially burned hydrocarbons.

I was hooked.

Even though I was well into my fifth decade when I finally got a ragtop of my own, it was worth the wait. Although not a Brit, “Zelda” our 1986 Mercedes 560 SL, roadster is the car J.R. Ewing drives in the opening sequence of “Dallas.”

In fact, when any 80s movie or TV show needed to suggest money and class, they simply ordered up a Mercedes SL.

The fact that she’s 27 years old, with 160,000-plus miles, a nice patina of dings and a Blue Book value somewhere south of a used Hyundai does nothing to diminish her timeless appeal.

I recently took Zelda out of storage for our traditional spring shake down cruise. Following a trip to the local car wash, we burbled through the take-out window at Starbucks and collected the usual chorus of oohs and ahhs from the hoi polloi.

The smiles and waves continued as we motored along, attending to mundane weekday tasks. As I prepared to leave the dry cleaner, a harried young mom exited her kiddie-seat-and-black-lab-equipped Volvo station wagon, paused, smiled and said “nice car.”

“Yup,” I nodded. “And the cheapest form of therapy known to man.” Responding to her blank stare, I explained, “You see, whenever I get behind the wheel, a couple of miles down the road I start to think.

“Hmm, I know I was worried about something. But, for the life of me I just can’t remember what it was.”