No wise pilot, no matter how great his talent and experience, fails to use a checklist.
The old believe everything, the middle-aged suspect everything, the young know everything.
What a fool old Adam was. Had everything his own way; had succeeded in gaining the love of the best looking girl in the neighborhood, but yet unsatisfied with his conquest he had to eat a miserable little apple.
理解就是知道什么导致什么。