I understand where you&#x27;re coming from, but it&#x27;s often the way questions are answered that&#x27;s the problem, as shown in your example.<p>If someone&#x27;s asking to put diesel in their petrol car, they obviously don&#x27;t know that&#x27;s a bad thing to do. Just asking &#x27;Why are you trying to do that&#x27; makes you seem like you&#x27;re trying to be difficult. A better answer would be &#x27;I think you&#x27;re looking at the problem wrong - diesel won&#x27;t work in your petrol car, what are you trying to achieve by putting diesel in your petrol car?&#x27;<p>Yes it&#x27;s a bit longer, but it actually helps someone know they are wrong, rather than coming across like &#x27;Pff you idiot, you want to do it my way&#x27;.