In the end of the chronological story, after the monster has succeeded in alienating Victor by killing just about everyone he has known and loved, Victor reevaluates his earlier choices, indicating he's questioning the personal convictions that underwrote those decisions. He says,
Learn from me, if not by my precepts, at least by my example, how dangerous is the acquirement of knowledge, and how much happier that man is who believes his native town to be the world, than he who aspires to become greater than his nature will allow.
Victor used to believe the acquisition of knowledge was the highest goal he could have, but he realizes now, having been isolated by the deaths of his loved ones, that this conviction has ultimately made him unhappy. In light of this isolation, he now knows he would have been happier if he simply stayed with his family and wife at home.
At the end, the monster says his "blood [still] boils" when he thinks about the injustices done to him; however, he says,
It is true that I am a wretch. I have murdered the lovely and the helpless; I have strangled the innocent as they slept, and grasped to death his throat who never injured me or any other living thing.
The monster used to be convinced of his righteousness, but, in hindsight — and now isolated — he realizes he became the monster the world thought he was and that his earlier conviction changed him.
Therefore, emotional isolation has a great deal of power to prompt a character to evaluate his or her earlier convictions.