On the 2013 finale of The Vampire Diaries...

- Enzo made Damon feel guilty about leaving him behind, as a scientist rescued him and he's spent the last 50 years as a test subject.

- In response, Damon accepted the fact that he's a monster and pretty much broke up with Elena as a result.

- Katherine collapsed and is on the verge of dying.

- We learned that Elena's dad did partake in some vampire experiments, but only to save humans. And one of the people he saved was Megan when she was a young girl.