If you want to be good at something you must want to do it, do it and strive beyond what you are capable of doing. If you do something on a average level and go, Im happy with this, you will not get better at it. And that at its essence is what craving is. And my next part is dangerous and do not take it lightly and without much thought. You must never be happy with what you know. In many cases, even what you have. You have a great wife and children, sure, be happy with them and do not crave for more wives. But in some things such as knowledge, wisdom and ability, you must never settle. And there are many more things beyond knowledge and wisdom that you must never settle with.