Last night I played a blank tape at full blast. The mime next door went nuts. Everything takes longer than you think. Left to themselves, things tend to go from bad to worse. If there is a possibility of several things going wrong, the one that will cause the most damage will be the one that goes wrong.
Nature always sides with the hidden flaw.
It always costs more than first estimated. If you try to please everybody, somebody will be disappointed. It is easier to get involved in something than to get out of it. Every solution breeds new problems. Whenever you set out to do something, something else must be done first.