I can't remember the first time I saw Jim Henson's magical animatronic adventure Labyrinth. I was not quite two when it was released in 1986, but my parents are massive David Bowie fans so it's not surprising I was introduced to it fairly early. I was hooked immediately, and watched our VHS copy – complete with adverts, having been recorded off the telly – so many times it eventually warped and then snapped.

I would shut all the doors to the living room of our small London flat, put the film on and act out each scene from memory as it played, pausing only to shout "don't come in" as my parents inevitably tried to get out of their bedroom, where my ritual had trapped them.

I was, of course, pretending to be Jennifer Connelly's Sarah, the imaginative, if immature, teen who is struggling to adjust to life with her father's new family and to her sisterly responsibilities to new baby, Toby.

Like my child self, Sarah is somewhat of a fantasist – she escapes the tedium of US suburbia by retreating to her books, reciting passages from her favourite, The Labyrinth: "Through dangers untold and hardships unnumbered, I have fought my way here to the castle beyond the goblin city to take back the child that you have stolen."

Reading on a mobile? Click here to view David Bowie's performance of Dance Magic in Labyrinth.

However, when she accidentally calls upon the story's cruel goblin king, Jareth – played by Bowie – to take Toby away, she's forced to embark on an expedition through a seemingly nonsensical labyrinth to rescue her half-brother from the castle beyond the goblin city.

But this isn't just a story about fiction becoming a reality, or goblins and Bowie's impressive trouser bulge: for Sarah, this is a journey into womanhood. As she passes through the labyrinth, she learns to cast aside the oft-repeated cry of "It's not fair" and instead tackle its deadly challenges and baffling riddles through logic, friendship and bravery. She is growing up.

Sarah befriends various bizarre creatures, and this motley crew – Hoggle, a particularly ugly dwarf; Ludo, a slightly dim, giant fur monster; and Sir Didymus, a heroic fox-terrier knight who rides an old English sheepdog – provided me with company as an only child. But as a teenager, it was Sarah's ability to make sense of a world that didn't make sense that drew me to her. Burgeoning new sexual desires had sent my head spinning and my body was quickly changing. People suddenly treated me differently, men looked at me differently and London was opening up as an overwhelming city in a way it never had before. I was scared and confused, but Sarah's perseverance in the labyrinth gave me courage and still inspires me to keep going when things get tough.

Reading on a mobile? Click here to watch the final scene in Labyrinth.

It's this cusp between childhood and adulthood, between hedonism and maturity, that Jennifer Connelly – 15 at the time of shooting – captures so beautifully. She is confident and good-looking, yet not as overtly sexual as women are so often portrayed on-screen – a much stronger female role model than many available today. However, the sexual tension between Sarah and the controlling Jareth is hard to ignore, despite Labyrinth being considered a children's film. When she finally reaches the castle, he begs her: "Just fear me. Love me. Do as I say and I will be your slave." But Sarah resists his attempts to seduce her. She has learned that she's in control – that she's now responsible for her own destiny.

"My kingdom is great. You have no power over me," she replies, remembering the words from her book and Jareth's kingdom dissolves. It's a line I often repeat to myself when dealing with real-life goblins.

• Why I'd like to be … John Cusack in Grosse Pointe Blank
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