Video is obviously a parody, but I've seen those types of people before.
Ignorance is bliss. One common thing I've noticed about drunks like that is that they have no self awareness at all, everyone is laughing at them and they have no clue, sometimes it spurs them on even more. If/when called out, they deny till they are blue in the face but it just makes it even more obvious. They are so sure of themselves, all for nothing. It would be sad if not for the fact that they eventually grow out of it. Most people anyways.