My first boss, one of the master plumbers that I apprenticed under so many years ago, had this poster framed in his office. Up until that point the words, "The Plumber Protects the Health of the Nation" never crossed my mind. However, without properly installed and maintained plumbing we would not be where we are today as a society. This is why it is important to hire a licensed plumber when a plumbing repair is needed.
My first boss had a saying. He had a lot of them. That is
another story for another day. He would tell me on occasion, usually
when I finished a particularly difficult task successfully, "Plumbing
looks easy until it ain't."