Your guess is as good as mine

Origin

This ubiquitous phrase, largely emerging in common usage during the 20th century, isn't born from a dramatic historical event or a specific trade. Instead, it springs from the simple, shared human experience of mutual cluelessness. Imagine two individuals staring at a perplexing problem or an unpredictable future; neither possesses a secret insight, and one declares, 'Your guess is as good as mine,' leveling the playing field of ignorance. It’s an idiom of humble honesty, a verbal handshake acknowledging that when it comes to certain uncertainties, everyone is equally in the dark, and all predictions, no matter how clever, hold the same low value.