Exactly. Veronica has some of the naivete that you'd expect from a 17 year old kid, and watching her grow is part of what's interesting. She's also started out a lot more skeptical than Buffy, since she'd already suffered whereas most of Buffy's suffering happened onscreen. And, yeah, Buffy had a sort of willful blindness... after she stabbed Angel and sent him to hell, she was still drawing hearts around his name on notebooks, and after he dumped her horrendously, she fell for Parker and then Riley... Veronica, in contrast, seems to learn from each of these situations and you can see changes in her behavior to reflect that. She's not likely to spend seven years repeating the same mistakes.