Yeah, that's good that you aren't too married to any curriculum. There really are these moments in child development when it is like a light switch. Yesterday they couldn't do it; today they can (or in gifted kid style... today it is too easy). It can be frustrating in the early homeschool years because so much is too easy or too hard... that "just right" category can be hard to find and when you do by tomorrow it is too easy!