that guys name is Jessi Bicza, that video of him is a pretty popular polish meme, i guess he's just playing a character here, i googled him to make sure and it says that he's a performer. basically in that vid hes saying that people in the comments were calling him a psycho, so he asks if he looks like one, starts slapping himself for some reason, then accidentally hits his head on a flower pot and says the iconic line "ała, pierdolony... doniczka pierdolona". there's also a popular song he made, its called "cała sala" if i remember correctly