I must admit I have had several ideas for a story that I never got around to writing down. I kind of slacked on they idea of writing for years, not knowing what I really wanted to do. And when I decided to write about my depression, I wasn't certain if I wanted to make it a novel or a memoir, but what I began writing sounded like a memoir.
And I must admit that I did not do any research at first, that came along later as I was I beginning t expand my story so it would be book-length. BTW, I now have over 80K words, and am still not done yet 🙂
A while ago, I started writing a dairy-style book set in the 1980s. I haven't done much on this recently, though. I now wonder what I should do to research this idea, even though I lived through the '80s. And I'm not sure how it's going to finish.
I didn't do any outlines either ☹️