Two years after winning an Oscar for his La Dolce Vita update The Great Beauty, director Paulo Sorrentino returns with Youth, a film which also evokes parallels with the work of Federico Fellini. This time, however, it's Fellini's 8½ which inspires another visually lush Sorrentino examination of the life of the rich and the regrets of old age.Set in an exclusive Swiss spa resort where everyone is rich or good looking, famous or a combination thereof, the story centres on two lifelong friends - English composer Fred Ballinger (Michael Caine) who has come to spend his regular vacation in the company of his daughter Lena (Rachel Weisz) and his oldest friend American filmmaker Mick Boyle (Harvey Keitel).As they ponder their failures as fathers and husbands, Fred and Mick cast a sardonic eye on their surroundings and the many grim-faced, well-dressed visitors who dutifully immerse themselves in the healing waters and take in the bracing mountain air of the Alps before dressing for austere, whispered dinners and the suitably dire evening entertainments.Not much happens but Sorrentino compensates for the aimlessness of the plot with visual sumptuousness, subtly sharp humour and a strong and refreshing chemistry between Caine and Keitel that quickly allows you to forgive them their bourgeois complaints and appreciate the absurdity of the environment. The emptiness at the heart of the life of the rich has long been an obsession of Sorrentino's and Youth is no exception - but it is surprisingly, less mournful and lighter in touch than some of his previous work.The vignettes of an overweight Maradona juggling a tennis ball in a brief recapture of his youthful talent, or of a sincere young actor (Paul Dano) testing out his latest transformation in front of a gob-smacked breakfast crowd, are deftly handled bittersweet comic gems. Hold your breath for the appearance of Miss Universe (Madalina Diana Ghenea) and marvel at the force of Jane Fonda's brief appearance as Mick's aging cinematic muse.But it's not all gentle fun and games and Sorrentino still asks some poignant and pertinent questions about aging, memory, regret and creative fulfilment that push the film through to its melancholic but effective conclusion. Even the people who inhabit the world of glossy fashion magazines and luxury-brand adverts have to inevitably face the same self-doubt and existential crises as the rest of us - they just get to do it in more style, with better hair, more expensive clothes and in places with better facilities.For now, in spite of Silicon Valley's investment in attempts to prolong it, life ends and youth is not eternal and, as Mick argues to Fred, ''emotions are all we have."..