When I read books like the Wheel of Time or The Gentleman Bastards series, it's clear that the writer has something much larger in mind for the series. While each book has its own self-contained story line, each is working toward a greater plot or ending.
It's hard to come up with such far-reaching consequences for seemingly inconsequential actions taken by the main characters in your books. A small decision made in the opening chapter of Book 1 may come back to haunt the character in the final chapter in the last book.
Being the writer of the story, you have to make sure that you track each important detail of each story. That's the only way you're going to have consistency across each of the books in a longer series, but it's also the one way to keep the story going. One book may only be one story, but it's part of a larger story. Any writer who has written a series with more than one book knows EXACTLY what I'm talking about.
But learning how to do that with our novels helps us to do the same with our lives.
The missus and I are talking about some pretty major decisions, both for our future and for the future of our kids. We're having to start doing small things TODAY that won't come to fruition for at least another few years. But the only way they're going to happen later on in life is if we take those small steps now.
What you are doing now is the first small action in the Chapter 1 of your Book 1. If you don't do that "something", you won't set off the chain reaction that will lead you through Book 2, Book 3, and all the other books of your life. You'll never get to "The End" of the series because you never took that first step.
I've had to dream big--both for the Last Bucelarii series, and for the life I want in the distant future. I don't know which will come to fruition first (the goals I want to achieve in my life, or "The End" for my character), but I do know that it's the small things I'm doing today that will help me to one day reach that "end" I'm working towards.
Start small, but keep that big dream in mind. It's really the only way that you're going to get anywhere in life!