Writing is kind of like chemical precipitation. You have a saturated solution that is bursting with a particular chemical, but it can't break into being a solid. It needs a starting point. If you put a single crystal of that chemical in the solution, the dissolved chemical will have something to latch onto and will begin to crystallise, and the crystal formation will grow.
With writing, you have all these thoughts, but, for some reason, you can't channel them into writing. There's a barrier there. Once you make a start though, it becomes a lot easier.
Writing is also like music. Just like the tension on the strings of an instrument enable a sound to be produced, the tensions of life yield the possibility of written expression.
