At the center of Epictetus' teaching is the attainment of happiness. A necessary condition is to know which things depend on us and which do not. Those that do not depend on us, we must understand that we cannot change them and must simply tolerate them, as it is futile to worry about them or to fight against them.

We can only change those that depend on us, and thus we can master ourselves in order to achieve happiness. This distinction made by Epictetus is particularly important. If we cannot make this distinction, we are doomed to consider significant those things that are actually insignificant.

For Epictetus, it is important to adapt to what happens in our lives and not to consider them bad or good, but indifferent. The indifferent, therefore, whether they have positive content (health, life, wealth, friends, family, etc.) or negative (death, illness, poverty, etc.), do not lead to the attainment of happiness, which is characterized by apathy and tranquility.

To face the adversities of life with calmness, without losing our inner peace, we can achieve this by properly evaluating the perceptions we have about things.