Quite often I find myself wanting to write about some more advanced topics. Something I find interesting and perhaps already know the basics.
Being able to write about such complex topics I usually find interesting isn't easy. Yes, I might know a bit more than an average person about the topic. But that's not enough to be able to write about it. When you have to explain something that you barely grasp yourself it probably just ends up being more confusing to the others.
So I need to learn more about those topics. Study them to truly understand them. The eli5 (explain like I'm 5 years old) is a good measure of subject matter understanding. But that might be a bit too extreme for some casual writing. I don't have enough time to get myself familiar enough at that level even one topic. The ones I'm interested about, just explaining the topic itself as eli5 wouldn't probably fit in 200 words.
It's better to assume some level of basic knowledge of the subject from the readers. Maybe start with my own level. If I can explain it to myself clearly enough, surely somebody with my level of general knowledge can understand it as well. I don't have to be an expert able to teach it to others. Just knowledgeable enough to be able to write about it.