Meaning of this portion of Jack Johnson's song, "Breakdown"?

I am a huge Jack Johnson fan and have often wondered this myself. I think he means that you just need to let go of your worries and problems and just enjoy what you have. The first stanza says that you can't really control anything if your mind just keeps on thinking about everything that's happening. You just have to let it go, get outside and enjoy the train being broken down, not stay inside the train. The third stanza is about how you can't control what happens to you and the fourth is about how you just need to let it go. That's what I think anyways. :]