The absentmindedness factor

Has anybody else ever created a complicated web of systems that each relied on each other to function and that were hardly intelligible in the test scene in which they were all placed together (I’m going to use external events, soon, after I test whether or not it works together) only to figure out that it did not work as intended, and then go into this here forum to type a few thousand words altogether (deleting the whole question a few times) just to explain that you need help figuring out how to do this … and then looked, and saw that the only truly visible problem at the moment, was that you were missing a condition in the Testing group of your events sheet – not in the actual systems themselves?