Anyone else wake up to a brand new kid one day?

Honestly its crazy around here. Its like a switch was turned on! Over the last couple days my son is completely different. It started a couple days ago with him blowing kisses and saying bye bye, and waving, then he started clapping, then he started throwing his hands up for "So Big!!" after he's done eating to tell me he's full, walking to the changing table and getting a diaper when he needs changed, and he's responding to nearly everything I say like he understands. He can do shape puzzles by himself now, pick out color blocks that I ask for, and his favorite thing to do is story time. Everything started happening a couple days ago! I seriously have a new kid in front of me, welcome to toddlerhood!! Anyone else have this happen? This rapid shift?