Reading! Really, truly, on his own, real book reading!
We've often noticed that teaching kids to read is like pushing a ball up a hill: it's work, it's work, it's work, then, suddenly, you're at the top. You can really read, so you do read, and the more you read the better you are at it; you're rolling down the hill.
After a very tough uphill climb (it turned out the letters don't stand still for him), Zorg is now racing down hill! Hooray Zorg!