How does one determine longevity, projection and sillage?


Story:
I work part-time at a department store chain similar similar to Macy's. I went to the fragrance counter before we opened and sneaked 5 sprays from L'Homme YSV. I used 5 sprays cuz I believe that my skin eats up scents. The sprays were put on my neck, 2x chest, 1x on each wrist, 1x on each elbow-crease.

How can I tell if my skin chemistry is eating away at the scent or was if my nose became numb to the scent?

I could smell it roughly until 3 hours after the sprays. At that point, I was taking a deep breath to see if I could smell it, which I could vaguely pick up.

FWIW, I liked L'Homme. It smelled like Belgiam Waffles with syrup and berries (Strawberries?) with a nice spicy note somewhere in the top note... I'm being serious.