Film-maker and actor Kris Rey is the cream of the mumblecore generation. Her 2009 debut about young Americans travelling and looking for new experiences in Costa Rica deserves attention simply due to its genius title: It Was Great, But I Was Ready to Come Home. Now she has made a beguiling comedy of manners: exquisitely awkward and painful, but also with a lovably broad streak of farcical absurdity.

Gillian Jacobs is Kate, a thirtysomething woman who is intensely stressed because her first novel has just been published and also because her relationship has collapsed. In this crisis of self-belief, she is flatteringly invited to return to her old college to give a reading and meet students – the invitation coming from her creepy (and married) former creative-writing professor David, tremendously played by Jemaine Clement. She once had a crush on him, and his clearly unaltered interest in her is now queasily complicated by his starstruck reverence for her career, which has outpaced his.

The moment Kate arrives back at her alma mater, she is stunned at how utterly unchanged it is, how warmly she feels about it and how ready she is to luxuriate in its reassuring familiarity, while also feeling an agreeable ego boost at being the visiting celebrity. Jacobs cleverly shows how overwhelmed Kate is to be here, and how happy she believes herself to have been as a student compared to her current uncertainty.

Slowly but surely – and very, very weirdly – she starts getting involved in the lives of the students who now live in “her” shared student house, inexorably regressing to her former student self. What’s so funny about the film is that it shows how very little divides your early-twentysomething self from your mid-thirtysomething self – you’re never too old to be humiliated.

• I Used to Go Here is on digital platforms from 14 September.