The golden mean is an idea from Aristotle. It is what we should all aspire to in our attempts to act properly. To Aristotle, all things can be good or bad. If they are done too little, they are bad. But they are also bad if they are done too much. It is only when they are done the correct amount (the golden mean) that they are good.
We can think of this in terms of personal attributes or in terms of things that we do. As an example of an attribute, if we do not have enough courage, we are timid or cowardly. If we have too much, we are rash or reckless. But if we have just the right amount, we are courageous or brave. Similarly, if we do not work enough, we will be poor. If we work too much, we might neglect our families or stress ourselves excessively. So we must work at the golden mean where we make enough money but do not have too much stress or spend too much time away from our families.
We must, then, aspire to find the golden mean in all that we are and in everything that we do.