Just when you get going, someone injects a dose of reality with a large needle.
Just when you get really good at something, you don't need to do it anymore.
Just when you think you've won the rat race, along come faster rats.
Knowledge based on external evidence is unreliable.
Laziness is the mother of nine inventions out of ten.
Leakproof seals will.
Learn to be sincere. Even if you have to fake it.
Left to themselves, things tend to go from bad to worse.
Leftover nuts never match leftover bolts.