Had she known what was disturbing Frankenstein, perhaps she could have found a way to help him. But he was alone in his misery, isolated by his own horrific error. It was his loneliness that made him savage. He had seen a family who loved each other and realized what he was missing. He had no one to comfort him, support him, or love him, and he felt that absence strongly.
Loneliness recurs as a theme throughout the monster's existence.
The monster desired the friendship of the De Lacey family and went about seeking ways to gain it by doing small chores for them anonymously and educating himself so that they would see past his horrid face. He watched their family together and saw the way they loved each other. He hoped they had enough charity in their hearts for him because he was a singular creature with no home or family, a being alone in the world. He wasn't an emotionless beast indifferent to his solitary state. He was sensitive and very aware of the isolation he experienced, so he wanted to reach out to the De Lacey family to end his loneliness.