Why?

So I was walking through a tunnel on campus today to get to my class and I realized that someone had been smoking in the tunnel. They had long since left, but the air in the tunnel had yet to clear out. As I struggled to breathe I thought "Why?" Why would you smoke in a tunnel. If you smoke outside it may annoy others temporarily but they can usually move, or else a breeze will provide some fresh air. Tunnels on the other hand don't cycle air very fast so everyone else has to breathe in your smoke. On top of this you can't change your route in a tunnel - you're stuck walking right along with the smoke.
I would find a nice way to end this blog but I'm sick so it it over in 5 4 3 2 1 .