Unfortunately, if you don't write them down - immediately - you WILL forget Even if you should later decide not to use them, it's good practice and re-reading your pages will almost always trigger even more and better ideas.
This book was designed to be carried around with you, so you can instantly jot down any scenes or dialogue that pops into your head.
There's plenty of room to start writing your book without fear of losing those golden thoughts
Write down any story ideas and by tweaking, mixing and matching, you will finish your book before you know it