At this year’s Oscars ceremony, Kristen Wiig, Maya Rudolph, Melissa McCarthy, Rose Byrne and Ellie Kemper lined up on stage to celebrate 15 years of Bridesmaids. Frankly, as awards bits go it was a little hard to watch, and the lineup was missing Wendi McLendon-Covey (recovering from a neck lift, naturally), but I had a small thrill seeing them together anyway: Bridesmaids has been my comfort film for almost half my life.

Bridesmaids, written by Wiig and Annie Mumolo and directed by Paul Feig, arrived in a confetti shower in 2011. It follows Annie (Wiig) – already in a fragile state following the collapse of her bakery, her relationship and her living situation – as she navigates being maid of honour for her best friend Lillian (Rudolph). We don’t see much of Dougie, Lillian’s fiance: it’s Annie and Lillian’s relationship that takes centre stage here. They have the sort of friendship it seems impossible to break, built on years of love, shared tastes and endless inside jokes – that is, until the wedding planning begins, and Annie finds herself ill-equipped to lead the motley crew of bridesmaids Lillian has assembled in the run-up to the wedding. No one poses a greater threat to the friendship or Annie’s headspace than Helen (Byrne), the perfectly manicured wife of Dougie’s boss. Helen is everything Annie is not: pristine, well-connected and apparently excellent at organising bachelorette parties. They clash constantly, with increasingly messy results.

In 2011, the dominant comedies were bro-y films in which women barely got a look-in, and I remember a heavy dose of scepticism among the mainstream media and my teenage peers about Bridesmaids. A film written by women, about women? Would it even be funny? As far as that era was concerned, if you were to take any pleasure at all in female-created comedy, it should come with guilt. For my part, I met Bridesmaids at a very “Sylvia Plath” time of my life, believing, like many 16-year-olds on Tumblr, that if I wanted to be a writer, I needed to a Serious One. Ideally a little tortured, but if I couldn’t manage that, then I should at the very least steer clear of light-hearted.

Of course, Bridesmaids proved its naysayers very wrong, very quickly. It grossed $306.5m at the box office and earned a couple of Oscar nominations along the way, but for me, it blew a tiny window – one I didn’t even know I wanted open - completely off its hinges. Here was a film with a killer script, wall-to-wall jokes, and an all-female cast, being … universally praised? Suddenly, being both light and taken seriously didn’t seem so incongruous, and my love of the likes of Nora Ephron and Louise Rennison didn’t feel so guilty. It allowed me to accept my own taste, and I watched the film repeatedly, delighting in seeing women on screen being as freely hilarious as those I knew in real life.

Then, at 22, recovering from a particularly blistering relationship – one that really distorted my sense of self – my best friend would put on Bridesmaids, sometimes night after night, to help me through the breakup. Studying for final exams, unsure of my next steps and untangling myself from someone who had been monumentally bad for me, my friend and I would share conspiratorial looks every time Annie’s mum earnestly tells her, “This is your bottom!” There was probably an element of schadenfreude in seeing someone else’s life implode, but if I’m honest, it was mostly nice to know that I still had my sense of humour despite the bruising my spirit had taken. From that point on, we watched Bridesmaids at least once a year until we could practically perform the whole thing off-book. It’s become a cornerstone of our friendship and our shared language: with each rewatch, a different line worms its way into our everyday lexicon.

Now in my early 30s, attending friends’ weddings and planning my own, it’s taken on new significance again. It’s certainly a cautionary tale of how not to approach my wedding, for a start – though I will say that it’s only now I’ve co-organised a hen party that I realise the many-layered brilliance of Annie’s bridal shower crash-out. The line “Did you really think this group of women was going to finish that cookie?” haunted us as we tried to ascertain how much cake was too much cake for 22 of our bride’s friends and family.

Beyond that, Bridesmaids does hold some bittersweet truths about this phase of life. At its heart, it’s about the fear of your friends moving on. It’s hard not to feel its pangs as your friends form new, deep-rooted relationships, but I take comfort in the film’s ending: Annie and Lillian dancing and singing to Wilson Phillips together, despite all the drama. It reminds me that if I ever feel that fear creeping in, I can always text my best friend with our current favourite Bridesmaids quote and know she’ll reply with the following line and a date for our next rewatch.

It reminds me that Annie is right when she tells her nemesis Helen that “we stay who we are” regardless of the directions we’re growing in. Those close friendships, like Bridesmaids, will always be there.

• Bridesmaids is streaming on Peacock in the US and on Disney+ in the UK and Australia