During the past month, I've been writing a book. It is a hands-on guide to Product Analytics from a Data Scientist perspective. The first hour in the morning is all about writing now. I limited it to an hour to avoid burning myself out and digging too deep. The goal is to distil my knowledge into something that I can see. I've got 13000 words by now and approximately 20% is done.
While writing it, I discovered something unexpected. Although writing a book reveals gaps in my knowledge it also shows how much I already learned. Impostor syndrome is a tough thing and I've always suffered from that. But writing a book helps. To put my knowledge on paper without doing any research I must know something, mustn't I? Once you start writing a book you eliminate half of the problem. That means you think you are knowledgeable enough to write a book, you think of yourself as a skilful and experienced person. It hits the Impostor syndrome straight to its heart. And I feel like it goes away, at least a bit.
That's my advice to you. If you suffer from Impostor Syndrome like many of us, start writing a book. Don't do any additional research, only structure things you've already learned. Don't aim for the audience, write for yourself.
P.S. I'm willing to finish the first draft by the end of this year. So, wish me luck :)