Have you ever stopped to listen to the things you say out loud or tell yourself in your thoughts? You have? How many times you've noticed you're complaining about things you can't do - things that are impossible?
I have news for you: most of the things you think are impossible in your life are actually not only possible but also perfectly doable. Henry Ford had his engineers build him a motor that they claimed was impossible. People used to think flying was impossible, or traveling to space, or speaking with someone who's on the other side of Earth. And look what were doing all the time now.
I heard one guy rode his bike from some country in Scandinavia to Mount Everest, climbed up to the peak, descended, and rode his bike back home again. So what did you say was so impossible in your life?
Going back to school while raising young kids?
Starting your own company in a recession?
Running two marathons in one go?
Living off eggs alone?
C'mon. Really. None of those are impossible. They may be hard, and you may have to do some organizing, but they're perfectly doable. All it takes is a little persistence from your part. And chances are that once you start believing you can do it, the universe will get out of your way and let you do it.
I know that sounds like some power of positivity bullshit - and if that's what you think, then perhaps you're not in a place in your head where you can take advantage of it. While I don't think the world will give you what you want if you just wish for it hard enough, I do think that people who want something bad enough will find a way to get it. If you truly believe nothing is impossible, you'll start acting like it - finding new ways to solve problems and thinking outside the box to make your dreams a reality.
People who think positively usually also behave positively, and this attracts the attention of other people, who think those positive people are invincible, so they'll will give them what they want. And suddenly, the attitude of those positive people become a self-fulfilling prophecy. Haters can hate; they never achieve anything and don't know better but to blame luck for the success of those who do not use the word impossible.
So quit telling yourself you can't do something just because it's hard or because no one else has done it before. You have no idea what's possible in this world. Might as well assume that everything is.