i am a firm believer that the most significant difference between the 74th games and the ones before is the berry scene. it is the concept that two people would risk their own survival, their own life, in order to save the person they love.
because it is not like all of the children that came before katniss and peeta were coldhearted killers. they weren't. in fact, many of them actively memorialized their dead peers. they saw the other tributes as people. people that deserved respect and reverence in their pitiful funeral.
however, for all of the tributes, their survival came first. even reaper, who offered a proper funeral for his fellow tributes, was very clear about his intentions to kill the others. and yes, he was sorry about it. but at the end of the day. he would kill them (tbosas, 191).
but for katniss and peeta, they just... couldn't. they couldn't let the other person die in front of them. let alone, kill them.
because although katniss's memorial for rue was powerful, it was not new. but the fact that they would rather die than live in a world without the other? that was the radical thing.