>>150217624
I hate having to try and parse Lucy's mind because she is clearly broken on levels I cannot comprehend, but here goes:

Lucy may not want to think about her attempt because it was proof of personal weakness. That's why she keeps brushing off outside concerns and only ever uses the fact that she did try as a weapon to hurt or shut other people up. Acting like the attempt still affects her ruins the illusion that Lucy is better now. She also may be focusing on Sandy because (A) Lucy has a preexisting obsession but also because (B) if she can blame everything that happened on Sandy's poisonous influence, then Mike is salvageable. Which means that Lucy is neither crazy nor pathetic for still wanting him.