That is true, but working through all the various possibilities will hopefully be an aid to understanding how things can go wrong. Anyway, we can't help ourselves.
Going down hill is easiest and streams tend to make a more or less clear path. Going down hill and trying to take the path of least resistance will naturally pull you into where the stream is. Plus your going to want water before long and now you have something to follow. It might be a ways, but that stream will eventually cross a road somewhere.