As September begins, it’s time to say farewell to the quintessential vacation snapshot: the iconic image of two sun-kissed knees. Whether posted on social media with hashtags like #bestlife or #bliss, or shared via text without any need for context, the message is clear: I am enjoying warm weather, indulging in leisure, and yes, I have knees.

Interestingly, despite the vast range of body types, everyone’s knees seem remarkably similar, and the backgrounds are often quite alike as well, featuring either a tranquil body of water or perhaps a scenic mountain view. Occasionally, a cocktail may appear in the frame, but rarely anything else that might disrupt the calm, such as a dog, which could detract from the serene vibe. Ideally, those knees would merely serve as a frame for a distant, intriguing scene—a lively sword fight or a parade of colorful horses—but that would contradict the intended message: “I am utterly relaxed and certainly not attempting to capture a photo with horses nearby.”

The season for showcasing knees kicks off in May, and by August, most of us have seen the knee shots from our friends. However, because they are so similar, it’s easy to forget whose knees belong to which locale, leaving us unable to gauge whose vacation was the most blissful. It would certainly add variety if someone would post a picture of their sunburned knees, but such an image is unlikely to be shared, just as any photos revealing mosquito bites or blemishes are often avoided. Yet, I’m not looking for a raw, unfiltered depiction of summer vacations; I simply want to be reassured that everyone I know—and plenty of others I don’t—has functioning legs.

Knee season runs almost parallel to football season, meaning that for the remainder of the year, we primarily witness the knees of athletes, which is perfectly acceptable. This observation is not meant to be disparaging; no one here longs for a time before smartphones and digital photography.

Zoe Williams is a columnist for The Guardian.