Early on in Adults, protagonist Jenny agonises over a caption for an Instagram post of a croissant. She auditions various phrases and hashtags, messaging her long-suffering friend Kelly for her input. Eventually, she posts the photo, and the waiting begins: “It’s like that conundrum of the tree falling in the empty forest,” Jenny muses. “Does it make a sound if there’s no one there? If you put something on social media and no one likes it, do you even exist?” It’s a scene that will make many readers wince, in a novel that acutely captures the anxious ruminations of a life lived online.