As English is not my mother tongue I had to look up the meaning of "Nerd" ! When I found out what it meant, I was not surprised that I never had heard this word because probably I am everything else but a nerd !
The best explanation I found was this one :
most nerds are shy ordinary-looking types with no interest in physical activity. But, what they lack in physical prowess they make up in brains. Tell me, who writes all the best selling books? Nerds. Who makes all the top grossing movies? Nerds. Who designs computer programs so complex that only they can use them? Nerds. And who is running for high public office? No one but nerds. ... Without nerds to lead the way, the governments of the world will stumble, they'll be forced to seek guidance from good-looking, but vapid airheads.
Linking to Linda G. Hill's One linder Wednessday-Nerd