In my children's novel, Steve Haven plods along (miserably). He thinks he knows what to expect in the life that has been plotted out for him. It isn't until all of that certainty is thrown into disarray that his real life begins
In The Inciting Event, Janice Hardy discusses just such a point in plotting your novel. She says, "The inciting event is the moment when things change for the protagonist and she's [he's] drawn into the main problem of the novel, or problems that will eventually lead to that core conflict". Have a look. It's well worth a read.