The harder the battle, the sweeter the victory.

谋划事情没有主见，就会被事情困住；做事情没有准备，肯定会失败。

Books are the quietest and most constant of friends; they are the most accessible and wisest of counselors, and the most patient of teachers.

I've learned that you can't have everything and do everything at the same time.

The only limits that exist are the ones you place on yourself.

解析：学问之道在于找回迷失的本心。