There was a survey-type of form at work I was filling out, and one of the questions was if I “needed” resource X. The few questions preceding this one had to do with resource X, and it was something I already had. Depending on how I regarded the question, it could require two different answers.
I concluded that the question was meant to ask if I needed resource X because I don’t have it, but the questions surrounding this one implied I already had X. So, for a moment I thought it was the opposite: that the form assumed I had X and was asking me if I needed X, in case someone else more in need could use it. If I answered “no,” I could potentially be offering X up to someone else.
It makes you realize how important user experience, particularly usability engineering, can be.