Star Trek: TNG - "The Unknown Possibilities"
A scene from the final episode (s07e25-26) of the "Star Trek: The Next Generation" - "All Good Things..." (1994)
The dialog between Q and Captain Picard.
P: I sincerely hope that this is the last time that I find myself here.
Q: You just don't get it, do you, Jean-Luc? The trial never ends. We wanted to see if you had the ability to expand your mind and your horizons. And for one brief moment, you did.
P: When I realized the paradox. ["We think it started in the past, but it didn't. It started right here, in the future!"]
Q: Exactly. For that one fraction of a second, you were open to options you had never considered. That is the exploration that awaits you. Not mapping stars and studying nebulae, but charting the unknown possibilities of existence.
—
Q: You're not alone, you know. What you were, and what you are to become, will always be with you.
—
And the very final line of the whole series from Captain Picard:
"So, five-card stud, nothing wild. And the sky's the limit."