I was sitting in bed in my hotel room in Portugal. It was midnight. All the lights were off. I had my headphones on. I was staring at my phone, completely locked in.

My biggest challenge was trying not to scream, which would have woken up the poor people in the next room.

Sleep was not an option.

My Celtics were playing the Atlanta Hawks in the first round of the playoffs last month. During the crucial Game 4, and I was in Portugal for the Estoril Open. When you’re a basketball fan living abroad, sleep is a real challenge, especially during the playoffs. You’re looking at a midnight tip-off for East Coast games in Europe. The games aren’t on TV in Portugal, so I was streaming it on my phone. Thankfully, the WiFi at the hotel was unreal.

When the Hawks went on their 14–0 run in the third quarter, it was 2 a.m. I was thinking, Alright, maybe you better just go to sleep. This is miserable.

Then Isaiah Thomas went off and got the Celts back into it. What an absolute boss. I love Isaiah. When he’s hot and he starts pulling up from everywhere, there’s no player I love watching more in the NBA. The dude is like the new Iverson. I might even have to start repping the green headband on the court like Isaiah.

The Celts fought back to force overtime, and I was pacing around the room like a madman. I think O.T. started at like 3 a.m. I’m trying not to scream during every possession, so I’m doing that thing where you just whisper to yourself like a crazy person.

Whispering, like: “Set the pick.… Come on, mate. Set the pick!”

When Isaiah hit the crazy off-balance three from the corner, that was it. I went mental. The Garden was going crazy, and I was jumping around my hotel room in the dark, celebrating by myself.

When the game was over, I stayed up looking at stats and recaps for another hour. I was jacked. I think I ended up falling asleep at like 4 a.m.

This is my life on tour as a Celtics fan. WiFi is a legit top-five priority in my life. You haven’t lived until you’ve tried to stream an NBA playoff game on your phone in China. Crazy day, that. This was back when the Celtics lost to the Heat in the 2012 Eastern Conference finals. The Internet wasn’t great. The picture was going in and out. I was losing the plot. It’s one thing to watch your team lose, it’s another level of pain when you’re watching them lose on a dodgy stream.

Brutal.

People always ask me, “How does a guy from Australia become a die-hard Celtics fan?”

Well, it’s a crazy story. I own like a dozen Celtics jerseys, but I’ve never even been to the Garden in my life. I’ve never even been to Boston, truthfully.

My love for the Boston Celtics came from video games. Back in 2006, when I was 11 years old, I got my first NBA Live game on PSP — that’s the PlayStation Portable if you’re not a big gamer. I was just starting to travel a lot for tennis all over Australia, and I needed a way to pass the time between tournaments.

I played a ton of basketball growing up, too. I was on an Australian junior-league team, and when I turned 14 I had to decide whether to focus on basketball or tennis full-time. But to be honest, I wasn’t too up-to-date with the NBA because of the huge time difference between the U.S. and Australia. Video games were my window to the league from the other side of the world. So when I got NBA Live I started flipping through all the teams trying to decide who to play with, and I ended up picking the Boston Celtics.

I thought the logo looked cool.

Remember, this was 2005, so they were one of the worst teams in the game. You absolutely cannot accuse me of being a bandwagon fan. I think they were rated like 76 overall. Fortunately, Paul Pierce was pretty sick. I think he was an 89 overall, and he had a unreal jumper. I fell in love with “the Truth” straight away. But they also had a crazy cast of characters — “the White Mamba” Brian Scalabrine, Ricky Davis, Wally Szczerbiak.

I didn’t just play games, though. I started a manager mode where you could run the whole team like a GM. When I wasn’t playing tennis, that’s all I would do. Kids now, they’re always online playing against their friends. This was 2006. I was just playing against the computer. That’s how obsessed I was with basketball.

This story might sound crazy to the older generation, but I know the same thing happens with the FIFA games in America. Kids start playing with Arsenal or Chelsea in the game and they really do form a bond with the team before they’ve ever watched the Premier League on TV.

Of course, I was dying for the real thing. I kept bugging my dad to get the satellite package so I could watch some real games on ESPN. After a few years, he finally broke down and got us a Foxtel box, so I would get up early on the weekends to see the Celtics tip-off. The 14 hour time difference was actually awesome on the weekends because you’d be watching a primetime game with your bowl of cereal. Winter in America is summer in Australia, so once the game was over I’d go outside in the sweltering heat by myself and pretend I was the Truth.

When the megatrade happened in 2008, and we brought in Kevin Garnett and Ray Allen, that might have been the happiest day of my life. Garnett is like my spirit animal. He’s my favorite player ever. Every guy wants him on their team, but nobody wants to face him. He’s so intense. The way he approaches the game is unreal.

As a tennis player, there’s a lot I’ve learned from how insanely competitive KG is — even now, when he’s 39 years old, he’s still a maniac. He might offend some people, but at the end of the day sport is about winning or losing. Everything KG does, he does to help his team win. How can a guy play in the NBA from age 19 to 39 and stay on top? There’s the only one answer. Competitiveness. Crazy, crazy competitiveness.

Everything in my brain always goes back to basketball. Everything is a basketball analogy. I’ll sit around with my mates and try to match people on tour with their NBA counterpart.

“Roger Federer? Oh, he’s Ray Allen, bro. So professional, day in, day out. He just gets the job done. He’s a Ray Allen for sure.”

You can banter about that stuff for ages.

When we’re on the road, I’ll always be on the lookout for a hoop so I can play some pickup. My game is not silky smooth, I have to admit. I’m more like a Trevor Ariza. Three-and-D, man.

People on tour will see me streaming games on my phone in the weirdest places and they’ll ask me why I’m so into basketball. I think it has something to do with tennis being such an isolated sport. You’re one-on-one out there. What I love about playing hoops is the team aspect. You look at a team like the Warriors, and their passing and chemistry are so incredible. It’s a different kind of sport. I just love it.

You should see my closet back home in Australia. I’ve got so many Celts jerseys it’s ridiculous. Pierce, Rondo, Bird, Garnett, Ray Allen. I’m hoping to add a Durant one in the future. Come on, KD! You’ll love it, bro. 😉

Of course, the Celtics ended up going down to the Hawks in six games, and I was crushed. But you know what? You can always get revenge on the PlayStation. When I finish my matches at the Madrid Open, I’m going to fire up the PS4.

Your season isn’t over, Isaiah. We’re gonna smash the Hawks, mate.