Dunning-Kruger - learn it, fear it. So long as you are aware of that effect, and aware of your tendency to arrogance (hardly uncommon, especially among the educated), you are far less likely to have it be a significant issue. Just be vigilant.
I have similar issues - I find it helpful to dive deeply into things I am very inexperienced with, for a while; realizing there are huge branches of knowledge you may be no more educated in than a 6th grader is humbling, and freeing, and once you are comfortable saying "That? Oh, hell - I don't know much about that, and will never find the time to", you can let it go and relax a bit. Or - I have. (my favorites are microbiology, or advance mathematics. I fancy myself smart, but it is super easy to be so totally over my head it may as well be mystic sorcery they're talking about. Humbles you right out.)
Big chunks of this board do that as well, FWIW.
We looked at the cloudy night sky and thought it would be interesting to share the ways in which, in the past, we made mistakes we would have been able to overcome, if only we had been stronger as rationalists. The experience felt valuable and humbling. So why not do some more of it on Lesswrong?
An antithesis to the Bragging Thread, this is a thread to share where we made mistakes. Where we knew we could, but didn't. Where we felt we were wrong, but carried on anyway.
As with the recent group bragging thread, anything you've done wrong since the comet killed the dinosaurs is fair game, and if it happens to be a systematic mistake that over long periods of time systematically curtailed your potential, that others can try to learn avoiding, better.
This thread is an attempt to see if there are exceptions to the cached thought that life experience cannot be learned but has to be lived. Let's test this belief together!