I just have to say it once, you just need to hear it. I love you, Elena. And it’s because I love you that I can’t be selfish with you, why you can’t know this. I don’t deserve you, but my brother does. God, I wish you didn’t have to forget this. But you do.
Damon’s first purely selfless act in the series is telling Elena that he loves her, go figure. This is one of my all time favorite scenes in the series because even though Damon prefaced this by saying it’s the most selfish thing he’s ever done, it’s actually quite the opposite. He loves Elena, he really and truly does, and he just has to say it once. The words have to come out, but rather that selfishly let her deal with that (because he knows how empathetic she is and that she would just fill herself with guilt over the fact) he lets the words out and makes her forget it.
At the end of season 2, when Elena thought Damon was dying, she kissed him. He had just confessed that he loved her (which, let’s be real, they both already knew) and wished that she’d known him as a human.
They’d come so far in such a short amount of time. Just episodes before, Elena was furious with him for force-feeding her his blood to ensure she’d live. Hell, in the beginning of this episode she told him she’d need time - possibly a lot - before they could be friends again. With the knowledge that he was about to die, she reevaluates pretty much everything and realizes that she does, in fact, care for him.