Yet another one that is basically impossible to translate until you get it wrong and see the answer...
I actually got it on the first try.
Das = that
Weiß = know
Selber = self
Noch = yet
Put two and two together, and you have "I do not know that yet myself," or as an American would say, "I don't even know that."
"Wissen" is a irregular verb. http://de.wiktionary.org/wiki/wissen_(Konjugation)