There are definitely external circumstances in life that we have no control over. eg: a global pandemic. However, what we can control is our reactions to these external circumstances.
Here's the thing—we get to decide the influence we allow the outer world to have on us. Let's consider a very mundane example:
A teacher assigns a class test for the next day. For the students, this is an external event they have no control over. What is the one thing they can control? Their response!
Some students will immediately evaluate the portion, create a study timetable, and get going. Others might spend hours complaining, blaming the teacher, and eventually decide there is 'no time' to study.
Now, let's do a small exercise:
You have complete control over the way you think, act & react. If we take complete responsibility for our lives, stop assigning external blame and simply focus on things in our control —it's shocking how much more we can accomplish. We have much more power than we give ourselves credit for :)