I like my life. I am not a worrier. I don't go around pre-imagining problems. This said, I fear porta-potties....
No-one likes them. They are an evil necessity, but I am confronted by my nemesis more than most.
My aforementioned life includes regular visits to construction sites. I carry a tape-measure and note-book and pencil. I speak "Contractor". My flat shoes and I are usually welcome as they quickly realize that I am a problem-solver and all I want is a happy client and a job that can move forward.
In my daily travels I sometimes need to pee. In order to use the facilities you first have to find them. Traipsing around the outside of a half-built house looking for that glimmer of blue-green somewhere up the hill or behind the tree. Wherever it is to be found, a porta-potty is almost guaranteed not to be set upon level ground, as if a rocking motion will add comfort to the experience. Sometimes one will be leaning drunkenly over a precipice. Sometimes it is deliberately placed in full view, front and center so everyone can see you struggle with the door and then listen for any sound effects. The best case senario is when p-p is to be found in a blue puddle. This indicates a recent cleaning and the possibility of toilet paper.
Negotiate the door; remember to relinquish note-book, tape measure etc. before entering. If it doesn't rock, don't be lulled into a false sense of security yet. Place feet slightly spaced and well centered on the floor. Execute a swivel and release button and zipper; being careful to gather up the legs of your trousers from the bottom so that they do not dangle on the damp floor. Assess your balance one more time and lower your backside whilst leaning forward. If you achieve stability of seating without changing the center of gravity you may survive another day without the dreaded Porta-Potty Tip Over.