The left bank is a state, a state of not being able to love a child. For Liang, it is Yi, and for Yi, it is indifferent. In the pursuit of love, they are both sad people. They are obviously very close to each other, but they are like the corner of the cliff in the sky.
In addition, Zuoan is also a kind of alternative and estrangement, just like Yi's ambiguous feelings for Momo since she was young. On the one hand, she acknowledged the influence that Momo had on her, but on the other hand, she hoped that she could be like an ordinary woman, at least it seemed that way, so she later had a relationship with Liang.
In our society, there are many people like Yi, who we generally call gays. They are in a different world than us, a world we don't understand.