From Rabindranath Tagore's "Lost Jewels," explain the character of Mani, in the light of the statement, "Mani did not understand Bhusan, it is true."

Mani, Bhusan's wife, does not understand her husband's gentle and accommodating nature and mistakes his gentle love for indifference or even greed. According to the schoolmaster who narrates "Lost Jewels," Bhusan is a modern man who treats his wife in too mild a manner. The schoolmaster says, "A man need not necessarily be ugly or poor to be cheated of his wife's love; but he is sure to lose it if he is too gentle." The schoolmaster maintains that a wife who gets gifts too easily from her husband and who does not need to cajole him into doing things for her will not love her husband. 
Mani is a beautiful and pampered woman who enjoys privileges without working for them. As the schoolmaster says:

"She used to get her caresses without asking, her Dacca muslin saris without tears, and her bangles without being able to pride herself on a victory. In this way her woman's nature became atrophied, and with it her love for her husband. She simply accepted things without giving anything in return."

In other words, Mani never has to sacrifice anything for her marriage, and she does not learn to commit to anything or anyone. She leads a very placid life, as she is not worried about her husband's love. She practices efficiency in running the house, and she never has to worry about losing her looks, as she seems to remain young forever. 
As Bhusan does not ask anything from her, Mani does not need to give anything and becomes selfish as a result. As the schoolmaster says of Bhusan:

"His love for his wife was of that kind which has to tread very carefully, and cannot speak out plainly what is in the mind; it is like the attraction of the sun for the earth, which is strong, yet which leaves immense space between them."

Therefore, when Bhusan loses his money and needs credit, he does have the nerve to ask Mani for her jewels, but she suspects that he will, as she doesn't know her husband very well. Instead of sacrificing her jewelry, she is convinced by her cousin to escape wearing it and is never seen again. The gulf that Bhusan leaves open between him and his wife--arising out of his gentleness--makes her suspicious. In that gulf, she inserts suspicion, and she never understands her husband's true goodness and love.