This common saying is essentially a cop out. It gives us the ability to stay the way we are and yet complain about why our life sucks. It is saying that we have no other way out so we will just accept it.
This mindset is so far off of what we teach the children in this world whether you are a teacher or not. If you are an adult, there are children who look up to you. You are modeling behavior for others whether you like it or not.
As adults, we know that there is always a way out. However, we put limiting beliefs in our lives. We know that change is not always easy and it is much easier to just accept what is happening and just complain about it to people we know will agree with us that there is no other way.
It is a trap that we either create for ourselves, or let ourselves get sucked into. Only you have the power to get out of it and change your current situation. You don't have to live unhappy. You don't have to wake up and dread the work day everyday.
I am not saying it is easy to change but making a small change everyday can help you get to where you want to be. You have to go out and look for it or do it. Without taking action there will be no change.