“Life itself is your teacher and you are in a state of constant learning” ~ Bruce Lee
Life will keep teaching you the same lessons over and over and over again until you learn and transcend that lesson with a passing mark.
That is why I believe life is the greatest teacher there is, because it will never stop taeching you.
So all you have to really do is to be a good student of it. Listen well, observe well, learn, master and apply.