Along the lines of what stupid thing have you done today. I know better than this.... I can't believe I forgot to close the black tank valve the last time I drained. Now I have a mess! A remin...
Lesson learned... LOL.. you will not do that again, for sure... BUT will be something new the next time! The list of "remembers" gets longer each time you take the RV out and length of time RVing has nothing to do with it.