When I took AP CS in C++, unfortunately, the finer details of iostream took up an inordinate portion of the class, which was particularly useless because iostream is really weird in a lot of ways (e.g. the stateful format specifiers sort of mixed in with the data being output). The part that wasn't taken up by that was taken up by memorizing some STL syntax.

Fortunately I actually taught myself programming in HS by writing mIRC scripts so I could do cool automation stuff in my spare time, and I had learned a little earlier in some kind of Logo course targeted at elementary-age kids. If it were up to that high-school C++ course to get me into computers, though, I would definitely not have done so...