Did you watch ‘Dead Poets Society’ again this week?

Secret Cinema, the international exhibitor that stages "immersive" film events, last night held several simultaneous charity screenings of Dead Poets Society in tribute to its star, Robin Williams, and presumably for those present there was catharsis amid the school ties and chalk dust.

The idea behind Secret Cinema is that ticket-holders participate in the "experience" of the film, which means dressing the part and embracing its spirit. In the case of Dead Poets Society this almost definitely means standing on tables in a re-enactment of its defiant final scene.

The first time I saw Dead Poets Society I was in a classroom and wearing a school uniform, not as part of a ticketed event but because it was an end-of-term Friday. By that point in the early 1990s, popcorn had been banned from the building as a result of its magnetic attraction to carpets, but end-of-term Fridays were still the best of days. It was finally time for the cathode ray tube and its newish cousin the VHS player to be wheeled in for our blinds-down entertainment and for what might now be called "teachable moments".

Williams, who died this week, was everywhere then; in the early years of Xtra-vision the exuberant trailer for Good Morning, Vietnam seemed to precede every rental. But his performance as the maverick, day-seizing English professor John Keating in the 1959-set Dead Poets Society is actually one of his quieter ones. Indeed, the film is really about not Keating but his students.

He has only to whistle his way into the classroom, and beckon them to follow him outside, and pretty soon they’re sneaking out of their rigid, elite prep school to smoke cigarettes in girls’ faces and make tribal whooping noises as they shuffle through woods in the dark.

Because I was young and impressionable when I first saw the film, its importance,and by extension that of Williams, chart off the scale, although if you were to measure the greatness of Dead Poets Society on a graph that plots its perfection against its importance, then you would of course have missed the point of the film.

Keating secures his status as an unconventional educator by getting his pupils to rip out a page of a textbook that reduces poetry to such a formula. He would much rather they create their own art and think for themselves.

Watching it as an adult is a rather different experience, not least because it turns out that one of the pupils is Josh Charles, who grew up to be lovely Will Gardner from The Good Wife (and he's just as lovesick in Dead Poets). As I have watched so many inspirational-teacher movies since 1989, the poetry-lesson scenes don't seem quite as electric as they once did.

Some things haven't changed, though. Dead Poets Society is still beautifully directed by Peter Weir and still performed with immense sadness by Williams – yes, even when he's doing the funny voices. "Are you a man or an amoeba?" he asks a pupil in jest, and the knowledge that he himself is surrounded on the teaching staff by amoebas is never fully verbalised, just there in his eyes.

For me, the bleakness of the suicide of one of the boys, Neil, after his father’s decision to remove him from the school remains undiminished by any subsequent “O captain! my captain!” gratitude the boys show their sacked teacher.

The tragedy is that Keating had dispensed with being a showman and given Neil solid advice, telling him to try to talk to his father, but Neil continues with the performance of the “dutiful son”, and that fatally conflicts with his desire to think for and be himself.

Dead Poets Society acknowledges, but never quite resolves, the contradiction between Keating's espousal of nonconformity and the way a rule-breaking club becomes its own conformity.

When one of the boys, buoyed by the carpe-diem mood, fails to understand it is time to be cautious, not daring, he more or less spoils everything for everyone else. Another boy thinks for himself by being a bit of a weasel and betraying his friends.

So while the standing-on- tables YouTube clips doing the rounds in the wake of Williams's death are a nice salute to his talent, Dead Poets Society shouldn't be reduced to the climactic display of solidarity that occurs in its final seconds, because both it and life are far too messy for that.

Shane Hegarty is away