In the community and in the media there is widespread awareness about many kinds of addictions – from drug and alcohol dependencies to food, sex, pokies and video games. As far as I am aware, however, there is a dearth of knowledge about a more, erm, esoteric kind of addiction: collecting Batman merchandise from the 80s and 90s.

This rather niche fixation beleaguered Darren “Dags” Maxwell, a former collector, a Melburnian and an active member of the Australian science fiction fan community for more than three decades. He is, along with his extensive Batman merch assemblage, the subject of Batman and Me, an Australian feature-length documentary premiering on Tuesday 30 June at this year’s online-only Melbourne documentary film festival.

Directed by Michael Wayne (no relation to Bruce), the documentary approaches its subject from an affectionate perspective but doesn’t turn a blind eye to uncomfortable aspects of Maxwell’s former life. Nor does Maxwell himself.

“Compared to addictions like alcohol and drugs, when it comes to buying things by choice, to a degree, I think it fits into the same category,” Maxwell tells Guardian Australia. “The impact on the individual isn’t so severe [on] a physical, psychological or emotional level, but the principles are effectively the same⁠ – where you struggle to control what you can and can’t do.

“I wasn’t going to sugarcoat it and put cherry blossoms on it, saying it was the greatest thing in the world. I bought these items and I couldn’t stand them. I hated them. I hate them today.”

Maxwell’s collection spans everything from Batman figurines to badges, board games, watches, trading cards, coat hangers, mugs, puzzles, pens and pencils and much more – even Batman ice-creams and a milk chocolate Batmobile, which he’s stored in his refrigerator for almost 30 years. Most of the items are in mint condition, sealed and unopened.

The documentary explores Maxwell’s addiction in detail: the way it consumed his mind night and day and, of course, the way it emptied his wallet. Maxwell says he was “able to break away from it all” and no longer has a desire to buy Batman merchandise, though this experience has had a lingering effect. Visiting eBay, for example, is never an option (“a complete no-fly zone”), and every time he purchases anything of any kind, he says he stops and interrogates himself about whether he really needs it (“all that stems directly from my collecting days”).

According to Maxwell, obsessive collecting can lead to hoarding – “a dark thing that gets out of control”. He knows several people who let their obsession get the better of them, including a couple who “at one point were hungry, and had no food in the house. And yet they’re sitting down looking at all these box collectibles in the room around them. That’s when it gets really out of control.”

Asked whether collections such as his are examples of consumerism gone mad, or can be justified as a kind of pop cultural archeology project, Maxwell says, “I think it’s mostly the former.” Collectors know they are being exploited, he says, but “you just can’t help yourself. You think: I still have to have whatever it is, because this is what I do.”

For Maxwell, the obsession began with the release of Tim Burton’s 1989 classic Batman, starring Michael Keaton in the titular role. As he recounts on his website (which looks like it was created not long after the movie premiered), he started by purchasing a 1990 Batman calendar. Then a Batman kids’ board game. Before he knew it he’d slid down a rabbit (bat?) hole, devoting an entire room in his house to a rapidly expanding collection, which he obsessed over.

In one laugh-out-loud moment, the documentary shows Maxwell in a toy store, brandishing a Batman figure as he explains to the camera that he used to be absolutely overjoyed to see children opening up Batman toys. Taking them out of their plastic packaging meant “I had one less to deal with in the world” and “my one at home would appreciate in value, just a little bit”. In another, he recounts how he once bought a Batman T-shirt from a person who was still wearing it.

Maxwell says the reason he quit collecting was not because he had an epiphany about the extent of his addiction; that came later. He quit because he was deeply offended by the quality of Batman & Robin, the widely derided 1997 blockbuster directed by the late Joel Schumacher. In Batman and Me, Maxwell, clearly still bothered by the film’s lack of quality, describes it as “a shemozzle from the outset.”

He is now open to the idea of selling his collection, which he placed in storage after the film was finished. But the ice-creams are still in his fridge, as is his very rare, very uneaten, very cold and very very old chocolate Batmobile. “I would be amazed if anybody else in the entire world has one of those,” he says, adding that if he sold his collection transporting those items would be “tricky”.

For Maxwell, the most rewarding thing about his collecting days wasn’t his collection per se, but belonging to a pop culture-appreciating community in which he found acceptance. The success of franchises such as the Marvel Cinematic Universe and Game of Thrones, and events such as Comic-Con, has seen this community come into the mainstream, making good on that old line about how geeks shall one day inherit the earth.

Addressing the explosion of fandom in recent years, Maxwell believes “social media has a lot to do with this. I think a lot of people were fans of pop culture stuff but were almost afraid, almost embarrassed, to show this to the outside world.”

Now, he says, “I’ll walk down the street and see people wearing Star Wars T-shirts and Star Trek jackets. That never happened back in my day.”

• Batman and Me is showing online in Australia as part of Melbourne documentary film festival on 30 June, and as part of Cinequest Film and Creativity festival 2020 in the US from 18 August

• In Australia, the crisis support service Lifeline is 13 11 14. In the UK, Samaritans can be contacted on 116 123 or email jo@samaritans.org. You can contact the mental health charity Mind by calling 0300 123 3393 or visiting mind.org.uk. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. Other international helplines can be found at www.befrienders.org