"Scent trails", I know exactly what you mean. I also have a very strong sense of smell. My friends call it my "dog nose". It was much more sensitive as a kid (I think), but still pretty good. I can follow people through buildings based on their smell (be it cologne or pungent b.o.) I can also identify people based on scent alone. Everyone has a very unique aroma. As a kid in school, I knew who had milk for breakfast. It was a very sour smell emanating off them -- probably why I find plain whole milk disgusting to this day.

Funny story, I found one of my favorite bars using this skill. Had just moved to a new location and it was super late -- everything was closed, but I was starving. I smelled tacos in the air. No idea where it was coming from, so I just followed the smell. After winding through a few small alleys, and up a few flights of stairs to this building, I ended up at a small late night bar. The owner was making taco rice.

My hearing is also quite good compared to my age. I still get bugged by those anti-teen/mosquito buzzers. I can still hear if an electronic device is on by the high frequency hum they emit. I attribute this to my actively taking care of my ears since childhood.

On the other hand, my vision is shit. Without contacts/glasses, the world is just a blur of color. I didn't know I had terrible vision until I got my first pair of glasses in middle school.