At the end of chapter 2 (of Mary Shelley's Frankenstein), Victor comments, "When I look back, it seems to me as if this almost miraculous change of inclination and will was the immediate suggestion of the guardian angel of my life."
What does he mean?
In order to understand what Victor means at the end of Mary Shelley's Frankenstein, one must examine what happens prior to his making of the statement.
In the paragraph prior to the one the above quotation is found, Victor admits to his consideration regarding giving up on moving forward with his "creation."
"I at once gave up my former occupations; set down natural history and all its progeny as a deformed and abortive creation; and entertained the greatest disdain for a would-be science."
Therefore, the statement Victor makes regarding looking back upon his choices in life (while telling his tale to Walton), Victor recognizes his aversion to science as one which, had it stuck, kept him from his tragic life. Ironically enough, Victor even calls his study of science as "deformed and abortive," a flash-forward of his Creature to come.
Essentially, if Victor would have acknowledged his distaste of nature as a sign from heaven, he never would have continued forward with his obsessive studies and experimentations. All of his loss, illness, and fears would have been averted.