OP - I think I totally understand you. I'm at the same point and have even seen the "auto-pilot" savings turn into a huge stash unexpectedly fast. At least for me, that adds another level of, "what am I even doing."
Anyway, after rolling this around in my head I have come to the conclusion that yes, "This is all there is in life." By that I mean, what else is there? Travel a little. Read a little (or, for me, a lot). Hang out with family and friends. Watch my three kids grow up. I continue to work because I am the business owner and can make all the rules. I've taken up gardening. I'm sure there will be some new hobby in the future. Yeah, that is basically it. There is no more big mystery about life.
I really like the prior poster's point that while we are younger we are always building for some future time when everything will be accomplished. I went to law school - seven years of building for something more and deferring today for tomorrow. Now seven years of saving, deferring today for tomorrow again. Now today is tomorrow. I've arrived at "tomorrow" very early in life. I, for one, have never lived in "tomorrow" and I'm doing my best to learn how.
In some ways that makes me feel "bored." I mean, I'll be reading, traveling, being with friends and family, and working for the next few decades. It will be variations on the same theme repeated over and over and over.
On the other hand, I feel content. I see some friends who have "made it" but they don't know it. They are stressed out because they have mental illusions they are chasing. A bigger house. More money (they can't spend because they are to busy working). Whatever. Chasing one illusion after another and always feeling a little unsatisfied when they seize their prize. They think, "This is what I was chasing? It was supposed to be more!" As said above, imagine waking up two decades in the future to that realization.
I will say, I've given myself some big goal to chase. But, I'm chasing it just for fun. I know there is no inherent value to the goal except that is an enjoyable way pass the time. I'll have some satisfaction just from completing a task I set out for myself. If, for any reason, I feel like this goal isn't serving its purpose of being a fun, worthwhile way to pass the time - I'll drop it like it's hot.
So, yeah. Long way of saying, "I hear ya." Your new challenge in life is simply finding enjoyable ways to pass the time - for decades.
P.S. Watch the movie, "Midnight in Paris." It always makes me think of this feeling.
