Nature photography can certainly be unpredictable!
There have been several times that I have experienced the wonderful sounds and sights of nature and missed out on picture opportunities. Sometimes I just sit down or lean against a tree and just breath it all in!
If everything in wildlife photography was always predictable and presented on a platter, I do not believe I would find it as challenging or enjoyable.
Bears, moose and wolves....I wouldnt mind experiencing some of that!