Quote Originally Posted by alexsms View Post
Hence, the shortened version - я не в курсе (I don't know about the situation, about it). Я не был в курсе - I didn't know about it, I was not informed, No one told me.
Note that "no one" is always written with a space, as two words, unlike "nobody".

Anyway, "not up to speed" (followed by "with/on/about this topic") is another good English colloquialism with the same basic meaning as не в курсе:

"We hired him because he's an absolute expert in cryptography, but it turns out he's not up to speed on PowerPoint, so we need to find him a secretary/assistant who can help him get up to speed (ввести его в курс)"

P.S. Don't confuse быть (не) в курсе -- "to be (not) up to speed" -- with быть в теме, which can be a sort of code-phrase for saying that a person is a member of the ЛГБТ-сообщество. "Он в теме" ≈ "He is a friend of Dorothy."