Elena, after everyone continues to convince her that she had once loved damon decides to run through the magic free, mystic falls border. So she does, and she gets glimpses of her and Damon but never fully remembers yet that she loves him. Damon pulls her back across the line and she asks about a kiss in the rain. He continues to try to get her to remember.
how does elena get her memories of damon back
decides to run through the magic free, mystic falls border