This is funny because it's true. Most of us are not our true selves in public like we are at home. Some things are better left behind closed doors! 
This BuzzFeed video is point on if you're a guy or a girl. Who would really sing Beyonce's 'Drunk in Love' aloud on a crowed bus? '"Surfboard, Surfboard"... unless you were in California, then it might make sense. LOL!! Who would order the whole menu on a date, appetizer, main meal then desert at home vs. I'll just have a salad. You don't wont to look like a pig.
The funny part is, this is so true when it comes to your spouse. You think they are one way, then you move in with them and they're a whole other person.