I keep using words like "useful" and "beneficial", when discussing Shakespeare's writing. I did it again yesterday in fact, while arguing that his work is more concerned with the future than with the past. Well, here's the case in point: The scene which takes place just after Hamlet has killed Polonius and has entered into a long confrontation with his mother, is often bypassed intellectually because we've been told that it shows Hamlet at a low point and reveals his character flaws and similar nonsense, but it actually contains a brilliant insight. First, we have to remember that Hamlet has just told his mother that she is now married to her first husband's murderer, and that she must try to stay away from him as much as possible:

Assume a virtue, if you have it not.

That monster, custom, who all sense doth eat

Of habits evil, is angel yet in this,

That to the use of actions fair and good

He likewise gives a frock or livery,

That aptly is put on.

(3.4)

Paraphrased, this means that human beings are very prone to "custom"(i.e. habit), and that our addictive personalities can either work for us, or against us. And if we get into good habits, we have a much better chance of reaching our potential - which I firmly believe is what Shakespeare was hoping to enable.