Stoicism is a school of Hellenistic philosophy founded by Zeno of Citium in Athens in the early 3rd century BC. Stoicism is a philosophy known for their teaching as striving for ‘virtue’ as its the only path to contentment. The philosophy asserts that virtue (such as knowledge) is happiness and judgment should be based on behavior, other than words. We are unable to control external events, however we would be able to control our response to them.
Here is a helpful video teaching the Stoics three ways of letting go. Despite these teaching are hundreds of years old, we can still use this philosophy and apply it to our daily life for us to live out a more comfortable lifestyle.