Kicking off the Glasgow Film Festival this year is While We’re Young, the latest effort from indie filmmaker extraordinaire Noah Baumbach. His last film, Frances Ha, was a stylishly black and white look at the aimlessness of a 20-something in New York. This feels somewhat like the opposite side of that same coin 20 years later, concerned not so much with “what do I do now?” but more with “can’t I be like I was?”

The film follows middle-aged married couple Josh and Cornelia (Ben Stiller and Naomi Watts), with a perfectly secure and by all accounts happy life. However, not quite ready to live the fully grown up life that is supposed to automatically come along with their age, they meet and befriend a much younger, hipster couple (Adam Driver and Amanda Seyfried) with whom Josh shares a vocation; documentary filmmaking. At first they thrive on the spirited energy the other couple brings but they soon begin to suspect their newfound companions aren’t as straightforward and sincere as they first thought.

On the surface While We’re Young seems like just another in a long line of quirky dramedies in which ageing characters complain. However, it’s with a ferociously witty, observant and comically relatable script that Baumbach more than succeeds in setting his film apart from that most crowded of crowds. The wonderfully drawn, expertly played characters are imbued with such a sense of believability thanks to the smart writing that really gives them room to breathe in their own story. And it’s a testament to Baumbach’s writing that even in some of the films more outlandish, even sitcom-esque broad situations – notably a scene in which Josh and Cornelia are invited to take drugs at some sort of ceremony – that it remains authentic.

The performances are uniformly great, from Watts as the wife desperately trying to cling onto the youth the newly befriended couple displays to man-of-the-moment Adam Driver as the effortlessly at ease documentarian Jamie, and in the case of Stiller I don’t think he’s ever been better. It’s the second time he’s worked with Baumbach (the first being in the under-appreciated Greenberg), striking a perfectly balanced dramatic and comedic chord as a character trying to get down with the kids, as it were, but slowly accepting that he’s simply not a “cool” 20-something anymore.

Quite apart from its tackling of issues like getting older and trying to relive the past, the film also explores the idea of authenticity in cinema, particularly documentary filmmaking, and what it means to arrive at a dramatic conclusion honestly. This comes to a head in a moment that seems at first like a cheap gimmick that threatens to derail much of the good work the film has done in the lead up. Thankfully it’s handled with a dramatic narrative precision so that it not only makes sense with what’s come before but is actually at the heart of what the film is trying to say.

There’s a lightness of touch to Baumbach’s latest film that makes it a breezily enjoyable, genuinely laugh-a-minute experience. But it’s that very breeziness that helps the film’s more dramatic moments to sneak up on you, particularly its cathartic, pathos-filled conclusion. It’s like the cinematic equivalent of a warm hug from someone who actually has something observant and important to say about life, growing old and acting your age. Wonderful.