So many ideas so little time

Having decided that I am going to write my book, I have found my head full of ideas.  It is hard to get my head to settle down and let me work on just one idea at a time.  I’ve found myself working on multiple ideas, basically just taking the time to write an idea down as it comes to me and hopping that when I get back to it, I will remember what I was thinking.  Come on brain lets work together here and get one thing done before starting on the next.