Something that might help is writing things down. For example, if you had a notebook where you wrote down things that you had figured out, every time you came to a conclusion, and any details that might help you remember why you came to that conclusion. Then, whenever you encounter a problem you can read over the notes in the notebook from a variety of topics, and see if any of them match. Also, if you keep it updated frequently then when you go to write something down that would be another opportunity to review the notebook and see if anything matches something else that’s bothering you.
Or if physically writing things in a notebook isn’t something you want to do, sending yourself an email could work in a similar way.
In general, I’ve found that writing things down helps with remembering things.
Sometimes a change is as good as a rest.
If you want to use your sense of wonder again, it might be good to seek out something completely new to you. Learn about something new, develop a new skill, or go to some place that you haven’t been before. Then spend some time being quiet and observing or practicing.
Or spend some time in person with people who are enthusiastic about things you are not enthusiastic about, and get curious about why they like it, and listen to what they say.
I’m pretty sure you still have a sense of wonder in there, waiting to be used. It may be something that grows with practice though.
Also, remember that familarity is not the same thing as comprehension! You may very well be familiar with more interesting things about the world than you were before, but that does not me an that you understand them! And Less Wrong is certainly not a comprehensive compendium of all the interesting things in the world. For example, a topic that is rarely discussed on Less Wrong is Fluid Dynamics, which is something that awakes my sense of wonder. Here’s a link to a blog about fluid dynamics: http://fuckyeahfluiddynamics.tumblr.com
I’m not sure whether to think up some strategies to help you find joy in the things you used to enjoy, or if what would help is spending time on completely new things, and making bigger changes in your life. Or some mixture, like remixing your past and present to make your future.
If there are still some minor things that you do find joy in, do those more often. Sometimes it is as simple as noticing what you like doing, what makes you feel even a smidgen happier, and doing it more.
I’m a bit confused as to how reading the Sequences could make it harder to find joy and excitement in minor things, or make you feel like you know everything. What happened, if you don’t mind sharing?