finish writing a book

I have tried so many times to do this. One day I will get a genius idea for a book. With characters, settings, plot lines, the whole shebang. I will be so pumped up about it that I will end up staying awake all night typing on my laptop. Sometimes I will write two pages and get bored with it or write forty pages and get bored. For all thirty word documents, all various lengths, I have on my laptop none are even close to being finished. So hopefully this year I will be able to actually finish writing a book.