When I decided that, oh, what the hell, I was a fan of Arsenal FC, the English Premier League club … I was concerned at being branded a front-runner.

Straddling the turn of the century, Arsenal won the Premier League three times in seven seasons, and this was when Alex Ferguson, the knighted coach of Manchester United, was still roaming the touchline.

The third of those Arsene Wenger-led Arsenal league champions, the 2003-04 club, went all 38 matches unbeaten, never done before or since, and are known, modestly, as The Invincibles. Not that I knew about it, at the time, given my generic disinterest in European club football.

However, by 2009 disinterest had morphed into a bit of interest, coinciding with a soccer-heavy, four-month stint on the sports desk of the International Herald Tribune, in Hong Kong.

In previous entries here I have mentioned crossing paths with Wenger in the press box at the Stade de France while covering a World Cup qualifier in the summer of 2009. (France versus Romania.) He was there to work in a broadcast booth, I believe.

He seemed like a decent, dignified man, tall and a bit patrician in bearing, but friendly with French journalists he recognized.

And, eventually, I just decided that I liked Wenger’s commitment to an attacking style of play, and that the club felt more like an international entity than something parochial and particularly English (like, say, Newcastle or Everton) … and that was that.

And how has that Arsenal decision turned out?

Not well, and getting not-weller.

–Arsenal has not won a league title since The Invincibles, in 2004, and that is 13 seasons of watching someone else celebrate, with Arsenal second or third or fourth — or fifth, such as last season.

–In lieu of league championships, Arsenal fans learned to accept qualification to the Champions League — which Wenger’s teams dutifully managed for 18 consecutive seasons — until that fifth-place finish last year, which dropped them into the Europa League.

–In lieu of any trophy at all … well that Champions League thing was supposed to keep Arsenal fans warm while the club won nothing from 2005 until 2014. Eight full seasons of nothing. (I was definitely not feeling like a front-runner anymore; especially when Arsenal went out in the round of 16 every year since 2009.)

–Arsenal’s best league finish since the Invincibles? Second in 2005 and in 2016 — the year Arsenal contrived to finish 10 points in arrears of Leicester City. Yes. Leicester.

And it isn’t just the final standings, it is how Arsenal gets there.

Wenger was a visionary, when he joined the club as coach in 1996, at age 46, with modern ideas on training and diet, in addition to his commitment to attacking football, and not just attacking football, elegant football.

But the rest of the league caught up to him, over his long tenure, and now he seems a stubborn old (68) guy wedded to a bygone era and a style that no longer produces results — even if Arsenal remains one of the world’s wealthiest clubs.

Wenger seems to prefer almost delicate, Smurf-sized players who have exquisite skills — but seem at risk of being pushed around by equally skilled players who bring a little more physicality to the proceedings.

Thus, a sense of a steady and inexorable slide into mediocrity, which is one of the worst outcomes for a group of fans. Water torture. Death by a thousand cuts.

Since 2005 … from perennial contender to also-ran; from Champions League sure thing to Europa League; from serial winners to three FA Cup victories, just when none of the big clubs really cares about the FA Cup till the final few rounds.

It no longer is clear Wenger or club executives have a plan. They seem loath to spend like the Manchester clubs do, and they have been losing their best players to other Premier League sides for a years now.

To this fan, the turning point was allowing Robin van Persie to leave after the 2011-12 season, when he led the league with 35 goals at age 29. Of course, he had been with Arsenal since 2004, when he was 21, and he had never won the league, so it made sense to sign with Manchester United — which promptly won the league as Van Persie scored 26 goals.

The latest? Alexis Sanchez to United; Olivier Giroud to Chelsea; Alex Oxlade-Chamberlain to Liverpool. Good players don’t really want to stay at Arsenal given that they have no belief the club is going to win anything important.

Or, in this case, they have no belief in a club that doesn’t make the Champions League or win the league anymore.

Wenger has just remade the attacking end of the club during the winter transfer window. Sanchez and Giroud out, midfielder Henrikh Mkhitaryan (from United) and striker Pierre-Emerick Aubameyang (Dortmund) in.

Maybe it will work out. Probably it won’t. Anyone paying attention to Arsenal has reached a sad, fatalistic place where the club can lose 3-1 to relegation-threatened Swansea (that happened tonight) and it elicits shrugs.

Arsenal has been really good at one thing, since I have been a fan, and that is in steadily reducing expectations.