On Chapter 10 of the novel "Frankenstein" the creature is speaking directly to Victor, reminding him about the misery and pain that Victor caused upon him with his ambition of creating a life. As he created the monster, the monster is dully Frankenstein's "Adam": His son, his own creature.
We find in the story that the creature, just like a child, had first begun life with the innocence that only ignorance of evil can bring. He only began to understand the evils of the world each time he felt like belonging and the world shun him mercilessly. He is alone, isolated, and depressed. He is particularly bitter and angry.
This quote is the summary of it all: He once was benevolent, because the creature never once intended any harm nor hurt to anyone, not even Victor. Yet, each time he tried to be a part of something, reality hit him with the bricks of cruelty. Hence, he became an angry, spiteful, and miserable living being.