No good deed goes unpunished. Leakproof seals - will. Interchangeable parts - won't. There is always one more bug. If you're feeling good, don't worry, you'll get over it.
Friends come and go, but enemies accumulate.
If you try to please everybody, nobody will like it. A short cut is the longest distance between two points. The chance of a piece of bread falling with the buttered side down is directly proportional to the cost of the carpet. No one's life, liberty, or property are safe while the legislature is in session. Anything you try to fix will take longer and cost more than you thought.