Exploration= curiosity
I became fascinated by space when I realized so much needed to be discovered and space was the place to try to satisfy our curiosity.
There was a discussion, here, some time ago, about the real motives behind Zubrin's Mars Direct. I thought he used the "colonizing" argument when actually, he especially wanted to explore Mars.
Colonizing is a step beyond, when our curiosity has been satisfied.
But that has not yet been the case, not for a long time.