If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.
译文：有钱有酒的时候，身边就有兄弟朋友，可遭遇困难的时候，身边哪里能看一个人呢。赏析：远离为了利益而交的朋友，结交相互欣赏，相互帮助的知心朋友。酒肉朋友再多也不如一个知心朋友。
"Psychology must bridge the gap between thought and action."