How it is supposed to work:
A group of cheerful, attractive, and vocally talented people approach a home while singing Christmas carols. As they arrive at the porch, someone opens the door with a smile and the occupants of home quickly come to see their visitors and begin to soak in the Christmas spirit. When the singing is done the listeners are touched thank them for sharing their talents. If the recipient is an older or lonely person they may even shed a tear during the performance or offer some sort of treat to the carolers. This is the ideal way you would probably see it happening in the movies.
How it happens in real life:
You hear people singing outside your home but you can't turn off your lights quick enough so you reluctantly open the door and you are immediately reminded how freaking cold it is. You obviously can't invite the big group in so you stand there shivering with a fake smile on your face. As you listen to their singing, you ask yourself "Are they doing this for me because they think I like it?". There is nothing more awkward than staring at a group of strangers who have showed up at your home to sing to you with no warning.
What it's supposed to be like:
How it feels for me: