>>172
Maybe he just referring to the forever unknowing possibilities of life scattered in the infinite universe?

One of the more popular answers has been that he's referring to finding life. However, the purpose of Starfleet has always been " to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.”

So far, the best answer I've gotten is that I'm to assign it whatever meaning I wish.

He's talking about thinking about things in new ways, as opposed to finding new things to think about. That was the whole point of the episde in which he says this. The implication, I suppose, is that either there's more to learn by examining what you think you know more closely, or that thinking in new ways, you ultimately improve yourself more than you do by just exploring space.

It's not particularly deep or mysterious.