Feelings of fear.
It is not a good idea to live as if you were going to disappear over night. Everything that is here today, will most definately be there tomorrow for you to finish or for you to continue. You are the one that continues what needs to be continued, to end what needs to be ended and to begin what needs to begin. Without you being here non of this is possible.
Every seed planted has carries the evolution of its existence within itself. It is born and goes forward from there. If we procrastinate our exist out of fear of the unknown then the seed does not grow, it cannot give it the life it was born to give you without your trusting in it. Trust that within yourself the seed is there and within that seed there are answers to who you are, to where it is that you are to go and to how it is that you are to be. The seed carries all of that, knows all of that, and without it we would not be here.