Fellow networkers, what's the worst 'I'm right' situation you've had that turned out you were actually very wrong?

Today A VPN to a 3rd party, used for one way access local client to host(across VPN) currently only allowing proxy servers in the remote encryption domain. We decide to bypass proxy, but instead of updating remote encryption domains to replace the proxy IP, its seemed more feasible to add a NAT rule where the proxy IP would be the NAT IP. Thus saving us aligning 3rd parties for changes etc.

Anyway I sent a confident email out saying that the NAT IP (also proxy IP) would conflict with return traffic as that proxy is still in use.

I quickly realised that I made myself look a fool.

Please feel free to send me hate messages.