One of the great analogies for growing in virtue is that of a battle against the passions and appetites. The particular virtues which are like a battle in the moment are temperance and fortitude.
Understanding virtue is so crucial for true happiness and success that you should probably read this page even if you don’t intend to read anything else at Virtus et Potentia. Essentially a virtue is a good habit. But what is a habit and what does it mean for a habit to be good?