After finishing the first drafts of my previous novels I debated about attempting to revise them. They were such a mess that I believed at the time that no amount of revision would turn them into good stories. So I didn't put any effort in there. Instead I started new projects to learn how to create a solid storyline, interesting characters, and so forth.
Now I have a first draft that I am happy with. It needs revision, yes, but the changes are doable. However, since I chose to focus on learning how to write better, I've spent very little time on learning how to revise and self edit. It's slow going as I read up on revision processes, and work through the draft. I've really only ever done revisions on short stories before this. That's a very different experience.
I also followed common writing advice to keep going forward through the first draft, not stopping to make changes or do extensive research when hitting spots where those things are needed. Instead, making a note about what is needed for revisions, and moving on. Now I'm doing that research, so I keep feeling that I'm not working on my novel because I'm not sitting at the laptop and typing. I keep having to remind myself that reading Michio Kaku totally counts at this stage of the process.
It really is fun to see the story get so much better with sometimes simple changes. While it feels slow, and I'm second guessing myself a lot, I'm enjoying this stage anyway. Hopefully it won't be too far in the future when I'll be ready to share the completed novel with you all.