Yes, I've learned a few things this summer. Some of these actually caught me off-guard.
I like reading more than I like writing. I think this is because I can read lightyears faster than I can write.
When the going gets tough, throw in an unexpected plot-twist. It seems to me, that the newest middle-grade books all employ this solution to problems. When the MC is backed into a corner, instead of working through the issue, the situation suddenly changes. I just have to remember that these authors have been published while I am not.
When doing intensive edits, it's disastrously simple to get frustrated and burned-out. Yes, my plans for the summer were sidelined by my frustration, and an intense longing to get healthier. I swam, I biked to nowhere (stationary bike), and I'm on my way to healthier.
Writing a book on an iPad comes with extra distractions. Games, news, etc...
Reading the news helps with writing sci-fi. For example, I learned about vertical gardening, which is very helpful in an enclosed habitat.
I also learned that I really do believe in my story, even though this fall and winter will bring another intensive rewrite. All I need to do is get started.