//*Insert But Nobody Came... music here* So basically, before the humans came, Flowey had control of the timelines. At first, he makes friends with everyone, but soon gets bored and kills them instead, taking much more interest in the latter. But remember, only Flowey and Sans have any real knowledge of the resests, so Monster Kid doesn't remember anything about Flowey. Since Flowey basically lives in the ruins, and once out, sneaks around unnoticed, MK doesn't see him anyways.