When I first entered the Temple, it wasn't that bad for me. It seemed like a normal forest/woods. But as I progressed further inside, I noticed that the Forest Temple is a building that is overrun by moss and other plants. And that, combined with the creepy music did change by emotions to more disturbed that at first.
And I'm assuming that this is the OoT Forest Temple, and if it is, this thread should be moved to the Ocarina of Time forum.
EDIT: it got moved. All good.