Paolo Sorrentino's sixth film is a light hearted but moving drama with echoes of This Must Be the Place and La Grande Bellezza. It's certainly a more accomplished and gripping work than his rather baffling early efforts, the snail-like Consequences of Love and the overly convoluted Il Divo.

Like This Must Be the Place, it's about music, and like La Grande Bellezza, it's about age. Michael Caine, in a remarkably subtle and dignified performance, plays a retired orchestra conductor spending time at a Swiss mountain retreat. The other guests – including a filmmaker (and friend of Caine's) played by Harvey Keitel and a young actor played by Paul Dano – are equally wealthy and somewhat neurotic in the way that only the very rich tend to be.

Caine's character is forced to confront his past – which is messy and causes him more guilt than we might initially suspect – when his daughter (a brilliant performance by Rachel Weisz) turns up with marital problems. Keitel's character, in a similar way, has to question the validity of his current life choices when one of his actresses (a fantastic cameo from Jane Fonda) mercilessly takes him to task.

Regular Sorrentino audiences will be used to his flashes of surrealism, and Youth is no exception. These are neither frivolous nor unnecessary; instead they are fine touches neatly woven into the film's narrative tapestry. Fellini – a great inspiration to Sorrentino – was known for his dream-like sequences, and was once considered the toast of Italian cinema because of them. The most self-referential aspect of it is the small part for Paloma Faith, a witty and surprisingly non-gimmicky touch which is genuinely hilarious.

It is all about the choices that we make as we get older; some of us carry on doing what we've always done, but increasingly badly; others abandon what they've always done well, though could re-discover it with equal aptitude if they chose to. Sorrentino's beautiful film is a sure handed meditation on how to grow, with his customary musings on all that is around us.

Fred Ballinger (Caine) is an ageing composer and conductor, holed up in an expensive Swiss spa hotel with his daughter Lena (Weisz) and his old friend from way back Boyle (Keitel). The film starts with an emissary from Buckingham Palace coming to beg Ballinger to conduct his most famous work, Simple Songs, for the Queen, which the composer refuses to do for 'personal reasons'. As the plot moves forward, there is some action – things happen, relationships become clearer – but mostly this film is about growing old and living. Ballinger and Boyle go for walks discussing old men's problems at the same time as the meaning of life: Ballinger talks to his daughter (also his secretary) and through her we find out what sort of a father and husband he has been. Youth is about what is important in our lives when we are young and what remains important when we are older. What do we remember? What will our children remember? And what is love? Is it the sad young woman who offers her services night after night? Is it the grand sensual passion of a new love? Is it growing old together?

I don't know Sorrentino's other films, but I gather that the mixture of ordinary and surreal is typical of his work. We mainly follow the lives of the guests but shots of the staff gathering early in the morning and taking up their posts in the restaurants or spas are interspersed with Ballinger conducting a herd of cows with cowbells or Boyle surrounded by all the leading ladies in films he has made. Some of the dream sequences are hard to fathom, some of the scenes and the characters have no relevance to the main plot; they are slice-of-life snippets. I guess if you spend a holiday in a hotel, you will come to know bits and pieces about the people around you – other guests or the girl who massages you – but this is superficial knowledge. Your life moves on without them and theirs without you.

Would I recommend the film? I enjoyed it immensely but it is a Marmite film and many people would be put off by the slow pace and jagged progression of what plot there is. But it is a visually beautiful film and the acting is first class.