He’s made music videos for the likes of Bob Dylan, The Beach Boys and Lou Reed, but as Rhiannon McGregor discovers, William McLellan’s road to success was anything but smooth.

“There’s something about knowing famous people when they’re poor and have nothing, in that bit before they get fame. That struggle is really fascinating,” says author, film-maker and celebrated music video producer William (“Willy Smax”) McLellan, recounting tales of “the glory years in Crouch End” with Annie Lennox and Dave Stewart of The Eurythmics. This sense of fascination is certainly true of McLellan’s own pre-fame struggle, which he revisits in his new autobiography, How I Got Into Art School (and out of prison).

Having produced videos for artists including Bob Dylan, The Beach Boys and Lou Reed, it’s no surprise that McLellan has a naturally affable demeanour. Yet his childhood and adolescence were not happy times.

His father was a pilot who was shot down three times during World War II – after returning home in a “state”, he spent time drinking and in jail, and McLellan’s parents eventually split up. This led to the child and his siblings spending time in a halfway house, where one day they returned to find nobody at home.

“It was a weekday and we were like, ‘Where is everybody?’” says McLellan. “My dad had already gone but my mum had left this note saying she’d left us, didn’t say where she’d gone or anything. The social services came and put us in a children’s home.

“I was eight, my older brother was nine, my younger brother was five and my sister was two-and-a-half. They split us up in different dormitories and it was really awful. I think that on the day I went into the home something happened to me.”

From an early age, art has been an important form of escapism for McLellan and formed the basis of his creative success in later life. “I’d been going to new schools all the time. When you go to a new school and it’s not the beginning of term, it’s half-way through, so friendships have already been made, you’re a bit of an outsider and art was the only way I could interact with them.”

After leaving school at 15, he endeavoured to turn this passion into a career, but to no avail. Originally from Leeds, he applied for Leeds College of Art and then Bradford College of Art, but his lack of qualifications thwarted his application for a grant from the council.

In 1972, disillusioned and desperate, McLellan and a friend concocted a scheme to move to Morocco and sell acid to the wealthy hippies living there. “We formed a plan that we’d work at London Zoo, which we did and it was great, and then we’d buy a load of art equipment from Camden Town art shop and then I had to score the acid. Which I did.”

Perhaps unsurprisingly, all did not go to plan, and after a run-in with Spanish police, McLellan found himself incarcerated in Franco’s fascist Modelo prison in Barcelona. The author recalls his seven months in prison with a raw sense of immediacy, recounting horrific episodes of cruelty by the prison guards, which were “very painful” to revisit.

Talking to McLellan, there is however the strong sense that this experience was instrumental in allowing him to escape the internal cycle of destruction that had been haunting him since childhood. The Buddhist principles he absorbed from his cellmate Mike made a particularly strong impression on the young artist. “What I liked is that if you don’t like where you are now, don’t try and change where you are, change your attitude to it,” he muses.

During his incarceration, McLellan was unexpectedly reunited with his possessions, including all his art materials. This served as his vaunted ticket to art school upon his release. “I got back, started building up a portfolio of drawings and took them to Hornsey Art School.”

Heralding a major turning point, McLellan was accepted onto the course with a special dispensation allowing him to acquire the vital council grant.

“Even though I live in west London now, we’re always coming back because our friends still live in Crouch End. My wife’s mum and dad lived there, on Middle Lane, so it’s always been our place.”

How I Got into Art School (and out of prison): A Memoir by William McLellan (left) is published by Old Street Publishing for £9.99 in paperback.