For me, it is knowing (or more accurately recognizing) when I'm going down the wrong path. Sometimes this is, of course, part of learning and sometimes it is a waste of time.
One thing great about the Internet and places like S.O. or H.N. or search engines, as well as other subject specific sites is it is much easier to find subject matter experts when you get stuck.
One thing great about the Internet and places like S.O. or H.N. or search engines, as well as other subject specific sites is it is much easier to find subject matter experts when you get stuck.