Write about something you think you understand.
Two things are likely to happen:
1. You'll surprise yourself with how much you know.
2. You'll be confronted with all the things you don't know.
Our heads are filled with untested ideas and beliefs. They're floating around, softly bumping into each other but not quite bumping up against reality. Writing is the act of catching these thoughts, connecting them, organising them, and confronting them.
Connecting ideas creates new insights. It creates eureka moments. It feels great.
Organising your thoughts brings structure. Structure strengthens arguments and makes for more robust beliefs. It also exposes the gaps in your thinking. For most of us, this does not feel great. It's a reality check.
Publishing – making your writing public – can be an even better reality check. Your thoughts can be scrutinised and criticised by others. When you read your own writing you are limited by your own knowledge and biases. Other people have different views of the world. They've experienced things that you haven't, which means they know things that you don't.
That's why it can nerve racking to publish your opinions. Doubt creeps in. You feel the effects of impostor syndrome.
This is good.
In fact, it's great.
You feel this way because you're testing yourself. You're vulnerable. What if you're wrong? What if you look foolish?
Welcome to the discomfort of personal growth.
Sharing your writing is a step towards change. You're pushing your beliefs up against reality and hoping it's a match. It's a test. A very uncomfortable test.
Publishing invites input from the outside world. Some of that input will boost your confidence. Some of it will not.
Every question and critique of your writing pokes at a piece of your identity. Your ego wants to hold on to what you know and believe. You're presented with a choice: change or stay the same. It's a choice that requires you to reexamine something very personal – your thoughts and the way you think.
Writing moves you further along your current path.
Publishing takes you places you didn't know existed.