It's okay! Anyone with 20 or so years' experience with the culture's “humour” will understand that it's clearly a joke. Duh. Stupid 10 year old for believing it

It's okay! Anyone with 20 or so years' experience with the culture's “humour” will understand that it's clearly a joke. Duh. Stupid 10 year old for believing it. I found the tone of voice most significant in this kind of situation. When it was “smiley, jokey”, I would get it was a joke – but even mock seriousness or, worse, exasperated parent, was completely credible.