I find Greg super hilarious but he isn't always a nice person. Editors often want a writer to make their characters likable -- especially editors of children's books. And yet, here you are with a best-selling series and a central character of questionable behavior. Are there techniques you use as a writer to make readers invested in Greg no matter what ill-advised stuff he does?
Honestly, I just tried to create a realistic portrayal of a pre-teen. When I was this age, I did and thought a lot of things I wouldn't be proud of today. My goal was to create a kid who didn't seem like he was manufactured by an adult. So I try to keep my books more or less lesson-free. I think kids respond to the books because they seem honest.