Three incidents that shaped Victor are Elizabeth joining his household, his mother's death, and going to Ingolstadt and meeting Waldman.
Most of us are shaped by our childhoods. We do not become who we are only because of the incidents of our youth, but what happens to us in our formative years can have an influence. Victor Frankenstein spends a great deal of time in the early narrative describing his childhood and youth. The author does this because she wants us to know that these incidents affected him greatly and turned him into who he became.
The first incident that had an effect on young Victor was the fact that Elizabeth came into his life.
I have often heard my mother say, that she was at that time the most beautiful child she had ever seen …These indications … determined my mother to consider Elizabeth as my future wife; a design which she never found reason to repent. (Part 1, Ch. 1)
Relationships and issues of love always seem to baffle Victor. Perhaps having a spouse ready-made for him at a young age might be a reason why. He never really understood how things work. She was more of a sister than a wife. He cared about her, but marrying her was an easy out. Pouring himself into his work might have been a distraction to avoid the real issue. He never communicated with her as well as he should
Supporting Elizabeth or communicating with her did not come easily. During the trial, Victor sits helpless.
My own agitation and anguish was extreme during the whole trial. I believed in her innocence; I knew it. Could the dæmon, who had (I did not for a minute doubt) murdered my brother, also in his hellish sport have betrayed the innocent to death and ignominy. (Part 1, Ch. 7)
He knows that the creature is the one who actually killed his brother, so it is actually his fault. Justine and Elizabeth are in this situation because of him. He pities Elizabeth, watching her testify, and Justine for confessing. He can’t say anything though, because it would expose him (and who would believe him anyway).
When Victor is seventeen, his mother dies. It is an event that seems to shake him to the core, and make him obsess about death.
I need not describe the feelings of those whose dearest ties are rent by that most irreparable evil, the void that presents itself to the soul, and the despair that is exhibited on the countenance. (Part 1, Ch. 2)
Victor is devastated by this. He still had to go to Ingolstadt to begin his studies, despite the fact that he is grieving. He describes how he goes through the stages of grief, including the fact that he cannot believe he will not be able to see and hear his mother anymore. This foreshadows his attempts to bring bodies back to life later, and his focus on what life and death are and the moments after death.
The final impactful event is when Victor meets M. Waldman at Ingolstadt. When Victor gets to school, the professors tell him he has wasted his time, and he believes that the books they assign are a waste. He is not interested in “natural philosophy.” He decides that the focus of science has changed.
The ambition of the inquirer seemed to limit itself to the annihilation of those visions on which my interest in science was chiefly founded. I was required to exchange chimeras of boundless grandeur for realities of little worth. (Part 1, Ch. 2)
Victor is not satisfied with any of his teachers until he meets M. Waldman. Waldman says he is happy to have gained a “disciple,” and Victor is happy too.
Thus ended a day memorable to me; it decided my future destiny. (Part 1, Ch. 2)
This is significant too, obviously. Victor is going to be making human beings out of body parts. He has to learn that somewhere! This man is giving him the building blocks of those skills. Until he met Waldman, he was alone and lacked purpose at Ingolstadt.
These incidents are important because in some ways, the monster in this story is not the creature but Victor. He creates a living human being out of discarded body parts and then abandons him because he is horrified by what he has done. The creature, thus abandoned and on his own, is left to fend for himself.
What the creature does is not completely Victor’s fault, but Victor does bear some responsibility. The person he became was shaped by the events in this chapter. His inability to show love is demonstrated by his relationship with Elizabeth, his obsession with mortality and creating life is shaped partly by his mother’s death, and his isolation and skills both are seen in the experience at Ingolstadt.
It is not that Shelley is making excuses when she includes these incidents for the reader. She is developing the character for the reader, and foreshadowing incidents to come. All of these events, taken together, help explain who Victor becomes and his later actions. Victor is a broken man. He is emotionally crippled. While he is arrogant and isolated, he is also sensitive and longs for human companionship. You can see all of these traits developing in the younger Victor. Nothing excuses what he does, but it does help explain it.