What do you wish you knew more about?

I wish I knew which life milestones were important and which ones I don't have to worry about. Or at least a more structured guide to life from someone I admire or trust. I'm a single 25 year old software dev, and am doing fine in most aspects of life, but feel like I'm missing some feelings of accomplishment and fulfillment. I guess what I'm looking for is a way to calibrate my feelings and emotions and general state of life.

Electronics, optical engineering, RF engineering, chemistry, physics, neuroscience, various mathematical disciplines, programmable hardware, various programming languages and paradigms, computers older than my father, computers I couldn’t possibly afford, etc...

There's a lot of things I want to learn more about and not enough time to do so. Time aside, it's also hard to know with which one to start. I find I get overwhelmed by the things that are out there for learning and end up procrastinating over it because I can't decide which thing I'd like to learn first, or how to figure out how to learn one of the things.

It's a terrible negative feedback loop, but these days information is so readily available, I find it a bit of a hurdle.