If the problem can be solved why worry? If the problem cannot be solved worrying will do you no good.
ShantidevaWhat need is there to say more? The childish work for their own benefit, The Buddhas work for the benefit of others. Just look at the difference between them.
ShantidevaAll those who are unhappy in the world are so as a result of their desire for their own happiness. All those who are happy in the world are so as a result of their desire for the happiness of others.
Shantideva