Mu Liang's drunken ramblings the night before had deeply moved her. Ever since he lost his memory, she'd been lost, afraid, raising her defenses like a hedgehog. He slapped her; she felt sorrow, resentment, and wished to return the slap, even crying out the harsh words 'break all ties.'
Did she truly wish to break all ties with Mu Liang?
No!
She didn't want that, and upon reflection, she suddenly realized that all their evasions and hurts came from their mutual failure to express their feelings.
That's why she had put up walls around her heart.
When he was drunk, he'd asked her sadly why she didn't love him, only the Mu Liang of the past, even though they were the same person.
She had never properly confessed her feelings to Mu Liang.
