The 'Septum Theory' is a viral internet phenomenon and satirical observation claiming that a septum piercing is a reliable indicator of a person's chaotic personality or niche interests. Often circulating on platforms like TikTok and X, the meme usually pairs photos of individuals wearing the jewelry with captions about 'red flags' or specific behavioral traits. While largely rooted in stereotypical alternative aesthetics, the theory has evolved into a self-deprecating joke within the piercing community itself. Users utilize this template to playfully categorize themselves or others, highlighting the humor in how a small piece of jewelry can become a massive cultural shorthand for a specific vibe.