The fastest I've ever learned anything was when I let myself be openly terrible at it.
Speaking broken Spanish in a Mérida market. Shipping a rough first version. Posting the video before it's polished. Every time, the same thing happens: being a beginner out loud pulls help toward you that expertise never could. People don't rush to correct the expert. They lean in to help the beginner.
Why we kill it
Somewhere we learn that not-knowing is shameful, so we hide it, and lose the exact state where learning is fastest and people are most generous. Beginner energy is the willingness to be seen mid-climb. It's not a phase to survive; it's a resource to protect.
A systems view
Every system I admire keeps a beginner's door open: low stakes to enter, fast feedback, permission to be bad first. I try to build that into products and into my own life. Staying a little bit of a beginner, on purpose, is how you keep growing after you "should" know better.