One of the most important aspects of stoicism is acceptance of the nature of the reality around you, and your current position in it. A lot of people mistake this for a lack of ambition and the suppression of all desire to make the world around you a better place for yourself and others. This is a fallacy. Acceptance of reality is not a surrender to reality, nor does it equate to resignation.
In fact acceptance of reality and your place in it means just that, and it can not be denied by an enlightened mind. That is to say, at this very moment, I sit in bed typing out on my tablet. I was born in an industrial age of a mammalian species on the third small planet orbiting the star Sol. My species has only just begun exploring the universe in a scientific manner, and they are still very primitive. They are warlike, unjust, prone to corruption, manipulative, and on a one way course for extinction via self destruction. I was born a peasant in a working class family in an economic and political system that highly favours those already entrenched in power. I am a slave to a capitalistic system that dictates that every man and woman must work a set amount of hours in a week in order to live. Which job I have and what my position in life is depends almost sole on a combination of the life I was born into and the information stored in my DNA. If I am not fortunate enough to be born twice blessed, then I am fated to suffer a life of drudgery and servitude.
This is the world I live in. I do not like. If I let it, it would fill me with anger and rage, hate and resentment. I hate it, but I accept it. I accept it because it is how the world is. That does not mean accepting it will always be this way. That does not mean resigning yourself to a life of slavery. That means understanding and accepting that at this present moment in time, this is how things are. This is my life, I did not choose to be born to this species at this time in this place to these parents with this DNA. It is not a choice that was made. It simply is what it is.
No matter how hard I try, no matter how much I care, no matter how unreasonable it is, this moment now is the present, and it is too late for anything other than acceptance of the place in which I find myself.