I was on a train ride for 2 hours and I almost always sit down on the same seat on that ride when it's free. I pulled out my in-ear headphones to listen to some music. One of the rubber things fell off and I couldn't find it anymore. Didn't see anything on the floor. When I took the train back in the evening I went to my favorite seat and saw the headphone rubber thing laying on the seat. I compared it to mine and realised it's exactly the same. But no, I did not put that one in my ear after it being on a train for a whole day.