i don't think they were savages per se, i think they were very much products of their environments, which encouraged them to be very unformulaic and unfeeling. however, when they were finally exposed to an influence such as mr keating, who encouraged them to subvert these values and enjoy english, and life, for its own sake rather than the... well, mathematical processes they'd been told to apply to it. also, the movie does take place over, more or less, 9 months, which IS enough time to change. there are a couple of lines/pieces of dialogue where i can definitely see what you're talking about, but overall i think they were just really trying to emphasise the effect keating had on these boys, and how it changed their approach to life.