People who self-diagnose and exaggerate in order to excuse their behavior. DH has a cousin who insists that he has 'migraines' and uses them to excuse him being an utter jerk or get out of doing things he doesn't want to do. However, when he has a 'migraine', he's able to spend hours online playing games, watching movies, etc. Bad headache? Sure. But he's never been to a doctor to get a real diagnosis. His latest announcement was that he has Asperger's, again totally self diagnosed after several people confronted him on his unpleasant and unsportsmanlike behavior during several D&D sessions.
What makes me nuts about this is that I know there are people who really suffer with various conditions, who have no choice and no control over them; for him to use the diagnoses to get out of taking responsibility for himself seems like a slap in the face to them.
...What a load of utter bollocks.
I used to suffer from migraines, and you'd better believe that TV, games, reading, and anything else that required visual focus or concentration was Right Out when one hit me. There are people who have migraines with no visual component / impairment, but they're rare, and they're still suffering from one heck of a headache! (Unless they have abdominal migraines, in which case they're probably doubled up weeping about the incredible stomach pain and cramps. Been there too.)
As for the Aspergers self-diagnosis, if somebody genuinely has Aspergers it's hard for them to learn social cues and how to behave - not impossible! It means they need to listen when people correct them and work to change their own behaviour, NOT that they get a free pass to be asshats. *grumble*
Your DH's cousin is just a <rude word>, Hillia, whether he really has those conditions or not.