On one side of the portal is your life as you know it. Everything is familiar. Life and you are just as you know it. As you step through the portal you are stepping in to who you want to become. The portal is the transformation from who you are to who you need to be.
This happened to me by getting married. Life is no longer the same as it was. I am not the same person in some ways. I have evolved and have become more. I will continue to step through portals and I will continue to become more.