I've spent alot of time walking around in the woods doing exactly what we're discussing, I'm speaking from experience not from movie watching. So unless I happen to frequent the most deserted places in Canada we clearly life in different dimensions.
And yeah I've had several situations where the noise in the wood was wildlife. I've stumbled into my share of foxes and deer and bear and wild turkey(funny shit) but I've reacted to the noises in the same way I would if I suspected it was people and just as many times it's worked to good effect.
Good on you ranger rick, so what do you do?
Because it sounds like your experience comes from remote ass parts of Canada where the wildlife sees human life maybe once a year, not from areas that see regular human life along the lines of what we are talking about.
Also there is a huge difference between someone walking and someone skilled sneaking. Also its called learning how to walk without making a sound (its not hard, just look where your stepping and move carefully) and no scent works wonders in not disturbing the wildlife.
Its not that hard to get to know the wildlife, just go camping for a month in a camp area/park it will blow your mind.