well that stinks

So I came home from work today, and grabbed my mail from my mailbox. I started heading up the hallway stairs to the second floor and I almost walked into a man going in the opposite direction as me. He was walking pretty fast and I was coming around a corner but we were able to dodge each other last second. When we walked by each other I didn't smell a thing, but after we passed one another I smelt a really awful smell that I guess he left behind. I guess now I know why he was walking so fast.