If you don't know where you are headed, you'll fall for anyone's 10 year plan.
I've heard of many people who start dating, get married, then wake up not sure if they are really living their dream life. Then divorce or affairs happen.
Maybe these people had 10 year plans and maybe they didn't.
But if you had a 10 year plan that was based on your true self and your true desires - not those of your parents, society, or friends, you are going to be a whole lot less unlikely to end up in a life you don't want. Even if you do you will have the confidence you'll know you can create the life that you want and get unstuck.
You might not know everything you want or things might change but it is always great to have a least a starting plan.
If you are dreaming big enough, the plan won't feel like you are being boxed in.
Writing a 10 year plan is difficult (but doable).
Go this blog to get the plan that I used. http://blog.lululemon.com/how-to-write-your-10-year-vision/
This website definitely helps break it down into smaller steps.