"Things change, Beast Boy. The girl you want me to be is just a memory."
When I watched Teen Titans the first time through, I finished episode 64, "Titans Together", and was like, "OK, that's the end of the series." But then I saw there was one more episode.
What was left to do, I wondered.
Other than sink some ships.
Thankfully, they addressed this somewhat in issue #51 of the Teen Titans Go! comic. In that issue, Geo-Force shows up and gives us Terra's back story and, more importantly than that, we get to see her with her school friends and she's...happy. Geo-Force even comments on it:
I bought the Golden Glider Heroclix to use for a different character, but as I started working on it, I started to see it as Terra. So, I decided to make it Terra as a student...but maybe sometimes she can't help but use her power. Or maybe it was gone and now it's returned.
Just like Terra.