The signs of maturity成熟的标志
You seek the signs of maturity
You're listening to the program; this action itself shows you are serious about being considered mature.
You now seem to shoulder your responsibilities and want to know the meaning of your existence.
Therefore, you are looking for things you should know/do in order to become a responsible and mature citizen. This is a sign of you now being a mature individual.
Maturity brings with it responsibility. With responsibility comes sensibility. Sensibility leads to confidence. So move with confidence to show the world you have now matured.
sensibility n.情感； 敏感性，灵敏度
Everything he writes demonstrates the depth of his sensibility.