I once saw a tweet that said, "Are you depressed or do you not live in a walkable city?" Sums it up. Similar to Sarah, I lived in Paris for about two years and the walkability plus excellent public transportation was life-changing. Love all of your thoughts! Also, in another life, I'd love to be making children's books too.
I lived in London for a year and got really spoiled to the walk your neighborhood and robust public transport for everywhere else. I was so healthy too from the natural (not pointless) exercise! I tried to walk when I came home, but my town just wasn't made for it. I'm glad you found a little car. I am partial to a hatchback myself.