Simply put, this mean that you have to quit complaining about how sucky your life is and make the best of the given situation.

This is no easy task, it's human nature to question the situations presented to us, most of the time we do not lie these situation, but what choice do we have?? we are our own master, we make our own choices and no one can take that away from us. but most of the time, we cannot choose what situation we are placed in. 

Yet all the time, we think, we act, we reflect... Is this really what i should have done??? What if i did it this way??? What if i did it that way??? These what if's constantly flood our minds with the endless possibilities of the situation. most of the time, we are unable to know if the choices we made are for the best, whether they are beneficial to us or if they have detrimental consequences. honestly we will never know, even if we have many lifetimes,  we won't even be able to experience the different paths we could have chosen and determine which one if the best for us. we live with our choices good or bad, we can regret all we want, try to change it all we want, but what's done is done. we all have our reasons for doing things, and we usually pick what we believe is good for us, and not necessarily what we want. so it is only natural that we look back and wonder what could have been, because our want is not satisfied, we want it, we want it, but what we want may not be good for us. so we choose.

Yet we are not independent from the world, the choices we make affect the people around us. we may indirectly hurt people with our choices. but that is unavoidable.