Also beg to disagree. The most important skill you can cultivate is wisdom. How you cultivate it is another story, though.
Yes, wisdom is vital, but if you don't have it then it's hard to develop. How are you supposed to bootstrap? It's like learning with no feedback.
Basically you find someone who is wiser than you and learn from them. Repeat. How do identify that person? Really depends on what kind of wisdom you are after.