今天，我导师提问师弟：种一棵树最好的时机是十年前，其次就是现在。这句话是谁说的？的确，我们在看到这句话的时候都知道这话的意思。是的，如果十年前你没有去种树，那么现在行动起来也不晚。然而，现在大部分人都表现得异常匆忙，why is everyone in such a rush? 这是博文Teach yourself programming in ten years 里提出的问题。大量的书籍命名类似为learn Pascal in three days，可是学习3天不足以让你写出significant program，也不能够吸收足够的经验教训，更不能让你跟有经验的前辈一起共事。我们用三天的时间学习Pascal 也许只能谈出皮毛，不会有深入的理解。就像Alexander Pope所说，a little learning is a dangerous thing。

    对于编程，最好的学习方式是learning by doing。To put it more technically, "the maximal level of performance for individuals in a given domain is not attained automatically as a function of extended experience, but the level of performance can be increased even by highly experienced individuals as a result of deliberate efforts to improve." AND "the most effective learning requires a well-defined task with an appropriate difficulty level for the particular individual, informative feedback, and opportunities for repetition and corrections of errors."