Mt.Ebott, the place where all monsters have been banished to its underground depths, and sealed by a magic barrier, preventing there "escape". It has stayed that way for many years, with only a handful of humans ever climbing the mountain.
And never returning.
But I'm sure you already knew that little backstory, so lets continue onwards at the entrance of the underground, where we meet a lonely talking flower named, Flowey. And here we se him... Talking to himself?
"Ahhh, It doesn't get better than this. A dark dank underground cave fit for a flower like me, where I can construct my next act of mischief, and evil doing." Flowey monologues to himself. The dark room fills with a few seconds of silence, before Flowey continues to talk to the very air around him. "Oh, who am I kidding? This place is BORING! I basically have the power to turn back time whenever I please, and I can't do a DAMN THING with it. Sure, I can just take the human souls from the old man, but that walking trash bag isn't as lazy as he lets on to be, and is keeping me from the very things that will make me A GOD. Now i'm just stuck in some kind of purgatory."
Being all alone, with barely anyone to talk to, and stuck in the underground what feels like forever to him, has put a toll on the flowers mental state.
"AND YOU, DR. NEEDLES, HOW ABOUT YOU STOP JUST STANDIND THERE, AND START GIVING ME SOME IDEAS!? I AM AT! MY! LIMIT!" Flowy yells at a potted cactus, witch falls over in response. (Somehow?)
...
"Okay, Its official, I've been down in this waste dump for far too long..."
"AAAAAAAAAAAAAAAA " *THUMP*
"What?" Flowey exclaimed. Just In the room with bed of goldenrod flowers, he heard what seemed to be a girl screaming and falling. It had been a long time he had heard something similar. Could this be... Another fallen human?
"I 'HAVE' been down here for a long time, but not much longer. Hee hee hee hee hee..."