The essence of exploring is moving beyond the boundaries of what we know. To drive our exploration we need curiosity.

Sometimes we find value that wasn't our goal

We can explore with a definite goal in mind in which case we're looking at the terrain around our goal to establish how can we reach our goal and what's involved in getting there. Another form of exploration is speculative; we suspect there is value and we are not certain. Sometimes when we explore we get a combination of both types; we start with a goal and find something of value we weren't expecting.

We don't have to explore novel terrain

Exploring doesn't have to involve something new, we can explore things we believe we know. If we believe a known situation has changed we can explore what we know to uncover assumptions and update our model of how things work.