How do you “know” what you are feeling?

I was with some of my family doing industrial cleaning at a job site. I walked into a locker room and my mind was immediately hit with thoughts of lust. I thought it strange for those thoughts to come on all of a sudden. Turns out, the room had provocative pictures which permeated the environment with that spirit. Has anything similar ever happened to you? If so, I would love to for you to share in the comments!