It’s difficult for me to explain my obsession with the Boston Celtics.

Even as an Australian, I have an affinity for New England sports; I trace this affinity to a promise I made to Helen, my American grandmother, in 1984. I was 9 years old and was seated on a stool in the Warren Lunch, the wood-paneled eatery she owned in Peabody, Mass.

Helen sternly asked me to “sit up straight” and pay attention. She then told me that, regardless of the fact that I lived in Australia, as her grandson it was my duty – nay, my birthright – to forever be a dedicated, devoted fan of the Boston Celtics, the Boston Red Sox, the Boston Bruins and the New England Patriots.

“You might have your rugby and your cricket – or whatever it is they call it – back home, and that’s fine,” she said. “But no grandson of mine is going to end up cheering for a New York team. You hear me?”

I nodded solemnly.

While growing up in Australia, I became a dedicated fan of Boston’s major professional sporting teams. Thanks to the generosity of family, friends and the occasional season-ticket holder patron of my grandmother’s bar, I took in many New England sporting events during the rare occasions when I visited America.

It was the Boston Celtics to whom I became most devoted. I took to playing basketball at an early age, there being little baseball, football, or ice hockey in rural Australia. I was also lucky enough to witness the Larry Bird, Kevin McHale, and Robert Parish era in person. Anchored by the original “Big Three,” the 1980s Celtics won three NBA championships, and their winning 1986 team is still regarded as perhaps the best in NBA history.

Watching a team of that caliber impressed me. My walls were soon adorned with Celtics posters and memorabilia, and I craned my neck for any news I could get as to the team’s ongoing successes and failures.

Unfortunately, after 1986 the Celtics’ fortunes changed. While the franchise had won 16 championships, the combination of cruel injuries, the deaths of two young future stars (Len Bias and Reggie Lewis) and sheer dumb luck (perhaps most notably the 1997 NBA draft debacle) cursed the Celtics to 21 lean years without another ring.

I’d been hooked long ago, however, and so through the 1990s and into the new century, I gritted my teeth and tried to cheer on a constantly revolving door of players that included Montross, Radja, Abdelnaby and Walker. At the start of the 2006-2007 season, Celtic patriarch Red Auerbach died at age 89, and the Celtics achieved the second worst record in the league with 24 wins and 58 losses.

I was now living in New England and enjoying the long-overdue successes of the Red Sox and Patriots, but my Celtics had become irrelevant among most locals.

We’d finally hit absolute rock bottom.

Then, in summer 2007, the Celtics made the offseason acquisitions of 30-something superstars Ray Allen from Seattle and Kevin Garnett from Minnesota to join long-suffering Celtics captain Paul Pierce on the team’s roster. Several key pieces to the “new look” Celtics franchise fell into place.

Expectations were high for Boston in the 2007-2008 season. Jelling cohesively, the Celtics secured the NBA’s greatest single-season turnaround and a league best 66-16 winning mark anchored by the No. 1 defense in the league. The Celtics struggled through two seven-game playoff series against Atlanta and Cleveland before toppling a tough Detroit Pistons team in the Eastern Conference finals. This, of course, set up a dream NBA finals matchup of Boston versus the Los Angeles Lakers.

I had awaited this since the glory days of the 1980s. It was great to see the Celtics relevant again among New Englanders. Above all, it was just nice for me to actually be here in person to experience it all. I secured tickets to Games 2 and the deciding Game 6 of the finals. There was no way that I would miss seeing the Celtics compete against the Lakers in the NBA finals.

Game 6 will always remain one of the most exciting, satisfying experiences of my life. From the get-go the Celtics played the kind of game that had already defined their season: selfless and ego-free and marked by intense defensive play with key contributions across the board from every single player on the roster.

As the crowd grew louder, the Celtics’ narrow lead mushroomed into a decisive, historical rout. Throughout the TD Banknorth Garden, fans reached levels of frenzied excitement capped by hugs and high-fives with total strangers.

Buoyed on by the memory of so many lean, lonely years as a Celtics fan, at about the four-minute mark in the fourth quarter, I suddenly caught myself jumping up and down on the spot, fists raised the air and screaming out in disbelief, “Holy cow, it’s actually happening! This is actually happening! We’re doing it! Holy cow!”

A hand calmly grabbed my shoulder from behind. The hand belonged to a Celtics fan who must have been in his 70s. Smiling broadly, he nodded and assured me, “It’s happening, son! Believe it! Title Number 17. Believe it!”

With that, 18,000 fans broke into a yell of “Seventeen! Seventeen!” that made my neck hair stand up.

Before I knew it, the buzzer sounded, and the building exploded into one blurred roar of deafening cheers. Players rushed onto the court in celebration, and green-and-white confetti poured down from the ceiling. The Boston Celtics had defeated the Los Angeles Lakers 131-92 to capture their 17th title – and their first since 1986.

As “We Are The Champions” echoed through the Garden’s speakers, I remembered that promise I’d made my grandmother in 1984 at the Warren Lunch, which had closed after her passing a few years ago. I contemplated with gratitude the experiences she had opened up to me by declaring that I become a Boston allegiant. I have passed the point of return, and you’ve only got my grandmother to blame.

I can still see Helen beaming with pride while approving of her Australian grandson’s unfettered loyalty to her hometown’s hardcourt heroes.

Evan Kanarakis is an Australian writer currently residing in Bangor.