I understand that a large number of people on this site are excessively shy in real life or feel nervous in many social situations. If you are one of those people, do yourself a favour and read that article - specifically the symptoms - and if you feel that you recognise any of those traits within yourself please, please summon the courage to talk to a doctor about it.
I've suffered from SAD (that's the official - and hilarious - acronym for it) for nearly a decade. I just assumed I was shy. I accepted it as how I was. Even when I read about the disorder it took me a year to work up the courage to actually talk to my GP about it. SAD is a negative pattern of thinking that is extremely difficult to break out of without professional help. And the saddest thing is the disorder prevents you from feeling you ought to talk to somebody about it. It traps you!
Chances are less than 1% of you are sufferers, but even if I can nudge just one other person toward getting the help they need I'll be happy.