Aww, that sucks. At least you don't have to worry about the mess now.

I've noticed it really easy for communal places to get messy since ot is easy to carry the ideology of "not my mess, I don't have to clean it" or become lax with their own mess. It's annoying.

Maybe you can talk to the manager or HR about trying to solve this issue. Everyone should be able to pick up after themselves and for the more routine stuff (mop, counters, etc.) maybe a weekly rotation with a different group in charge of cleaning might be a good idea so that all the work isn't left to you after things get built up to the point of being unmanageable.