I just celebrated my 50th birthday and have visited the park at least once a year, almost yearly. Over time we have seen a few bears in some interesting situations. Last year while fishing along the road along Elkmont i began noticing different animal tracks streamside. I first saw some prints by what appeared to have been a bobcat or lynx. The prints were wet and had almost perfect outlines on a couple of streamside rocks. As I continued fishing downstream i looked down and there were big paw prints in the mud, apparently bear prints and you could see the outline as well as some scratch marks. I figured they could be old prints, but as I continued looking there were some similar fresh and still wet looking prints on surrounding rocks leading away. I looked for a bear, but it had apparently left before I had seen it. How much earlier I don't know which caused me to wonder how many times bears see us without us having much of clue they were even there.
Asa kid I recall the drive and stop process when you'd see folks parked and standing with cameras in hand, universal signal for bear
Once when my parents pulled off to get footage on the Kodak Super 8, this big ole boar bear was standing with his paws inside a 55 gal trash barrel. In a few minutes he stood back and withdrew his paws with what looked akin to flypaper. As he continued to wrestle with it, it turned out to be a bumber sticker and as he seperated his paws you could read it. The funny part was the sticker read, "See Rock City".