What is the Root of Knowledge?

I've been thinking a lot about what makes people want to create, invent, innovate, learn.  So many of my colleagues and friends are innately curious and I know that, for me, learning is an addiction.  So, appropriately, I was reading one of my favorite philosophers/theologians and found this:

“Wonder rather than doubt is the root of knowledge. Doubt comes in the wake of knowledge as a state of vacillation between two contrary or contradictory views; ... the business of doubt is one of auditing the mind’s accounts about reality ... “
— Abraham Heschel, "Man is Not Alone," pg 11

We certainly learn through doubting - we gain knowledge and insight by doubting, questioning, and even doubting our doubts.  But at the root of it all, what gets us to doubt in the first place, is our ability to wonder, to ponder, to think.  

How much more would we learn if we could wonder as we did when we were 4 or 5 or 8 years old? What can we try to truly wonder about this week? I'm curious!