Knowledge is like a tree. Take care that the trunk grows strong, and the main branches healthy. It is this strong foundation upon which every else will hold. If you do not pay attention to them, you will soon find the leaves all fall away the slightest disturbance. There’s no use in making countless branches if the base cannot support the weight. The whole thing will simply come crashing down. But if the trunk is strong enough, it can even withstand the passage of time..