Abbie's poem plays with a neat little paradox: if you claim you have no secrets, that's the biggest sign you do. The speaker's logic is simple but a bit unsettling. A "real" secret is one so well hidden that you haven't admitted it even to yourself, so denying you have one is exactly what a deep secret would make you do.
The speaker sounds playful and knowing, almost like a friend teasing someone who insists they're an open book. But there's a quieter note underneath. The last line, "You are that secretive that you never told yourself," suggests that some part of us stays hidden from our own view, and that idea is a little lonely.
The mood is light on the surface and thoughtful underneath. The short, plain lines and the repeated word "secret" make it feel like a riddle that you turn over in your head, and it leaves you wondering what you might be keeping from yourself.