Maturity ..

Be mature enough to know that life is not linked to people ..
Life is up to you ..
Be mature enough to expect the unexpected .. To know that people are not always the "Angels" you thought they are .. To realise that they can never show you their real faces by the first time you see them .. To believe that first impressions are always fake .. 
Be mature enough to learn how to ignore things .. Deeds .. People around you .. To pretend that your life is wonderful just the way you want it to be though it is not .. To know that telling your problems to people will not solve them .. That you shouldn't take your decisions on the basis of people's opinions ..
Be narcissistic if necessary..
Be mature enough to know that planets turn around the sun .. Not around people ..
Be mature enough to enjoy life the way it is and to focus on the brightest side..
Be mature enough to know that you're never mature .. Until you know that maturity is a policy ..