Hmm...well...definition of a nerd is "a stupid, irritating, ineffectual, or unattractive person" and also "an intelligent but single-minded person obsessed with a nonsocial hobby or pursuit".
So I agree with being unattractive and somewhat intelligent, but I hope none of the other stuff applies cuz then I sound horrible.
Have you ever broken something valuable and never told anybody about it, then when finally asked about it/how it was broken you just said "I don't know"?