This is one of those things that I think most of us don't think about too often. Maybe it's better put another way - maybe we do think about it, but we don't do anything about it. The thinking of it and not doing anything is a major problem that we cause for ourselves. (a lot of personal experience in this area for me).
As we get older, it get's easier and easier to let the circumstances and other outside factors dictate what we do with our lives. We get to a point where we just go a long and focus on taking care of our family, paying bills, trying not to go into too much debt; or if we do, we spend many yeas focusing on getting out of it. We keep working at our jobs that have kind of taken over our lives and we sometimes get stuck there thinking that we have too many things riding on our jobs to make a change. It's too scary to make a change in trying to design our own life and go after the things that would make us happy, just because we are too hesitant to risk the status quo of our lives. So most of us that hesitate like this do indeed fall into someone else's plans - our job, the government, creditors, etc.
The sooner we are able to go after our own life design, the better our lives will be. When we don't control our own lives and give up that control to outside factors, that leads to an unsatisfactory life. Along with a very expensive unsatisfactory one where I'm not just talking about money. What do you think are some other areas that get "expensive" in our lives if we give up control to outside factors? I'm always very interested to hear your thoughts and opinions because usually not only do your thoughts help me - they can help others too.