Just one example: All my life I have been curious about human pre-history and ancient history. Never learned much about it along the way.

Now that I have time, I find an incredible wealth of knowledge and insight about early human history has been developed. I feel like a dim area of my understanding is being illuminated, like exploring a dark attic with a bright flashlight, it is very satisfying, and particularly when pieces fall into place and I have an "aha! so that is what that was all about" moment, it is exciting as well.