no chewing in the gym room

when i went to the gym the other day and stepped onto my usual machine, i noticed that someone had left a piece of chewed gum on the machine's magazine holder. who would do this? why would someone leave a present for the next person to use the machine? maybe the person forgot to throw away the chewed piece of gum after working out. but that doesn't explain why someone would place gum there in the first place! there are 2 trash cans within twenty feet of the machine as well as paper towel dispensers to put the gum in. so, much to my disgust, i had to remove said piece of gum with a paper towel and throw it in the trash. thinking my gum troubles would be over with that gym visit, i went home and i saw that someone had take the effort to place a chewed piece of gum on my front doorstep! now i live in a single family house at the end of a cul-de-sac. so there is no reason anyone would even pass by my house. and even if someone just happened to be walking down to the end of a dead end street, they would have to walk the extra thirty or so feet of walkway just to get to my doorstep! would someone purposely walk all they way up to my doorstep just to spit out a piece of gum? or maybe i'm going crazy and i'm leaving gum all over the place?