My favorite definition of courage is, roughly, "being afraid to do the right thing, and doing it anyway."
I've always viewed technical writing as a courageous act. In a world of petty arguments over tabs vs spaces, vim vs emacs, and React vs Vue.js—strongly (though increasingly jokingly) expressed opinions over largely incidental things—the idea of trying to assert any level of implied authority feels like a foolish investment of time and energy.
Then there's the issue of not feeling like an authority. I've been writing code for nearly twenty years now, and half the time I feel as lost as I did on my first day at the keyboard. How could I possibly add value when I know so little?
And yet, when I take a moment to analyze the resources I've found most useful—whether blogs, or books, or tweets, or videos—it's always the person just ahead of me on their journey that I resonate with the most. Intuitively, this makes sense. Having just been where I am, they're in that sweet spot of maximum empathy meets maximum utility. They don't need to be experts. They know what I'm going through, and know exactly what I need to do to overcome my current obstacle—and that's enough.
The same is perpetually true for you. Somewhere out there, someone is facing the exact same challenge that you just overcame, whatever it is.
So... share your experiences. Don't worry about how someone will interpret them, or if someone will think your opinion is wrong, or stupid, or naive.
Write courageously, safe in the knowledge that at least one person will find your message, learn from it, appreciate it, and hopefully pay it forward.