 This trend is, without a doubt, a result of both self-delusion and deliberate fraud, and often kind of a mix of the two. Maybe it begins as a deliberate fraud, and then people actually succeed in convincing themselves that they really have it. I used to be very good at this kind of thing when I was a kid. When I would pretend that I was sick so I didn't have to go to school, and then by late morning, I'd actually start feeling sick because I was so good at acting the part.