If you're going through some form of emotional upheaval it's always comforting to know that someone has gone through it before you. This helps you to not feel so alone. It also helps other people identify with what you're going through even if they have only experienced it vicariously.
For instance, if you and your partner or significant other are splitting up, most people will understand what you're going through. The memes are in place.
If, on the other hand, you tell them that your wife is an FTM transsexual and will be transitioning into a man, no one but a SOFFA will even understand what that means, let alone that it's even possible.
You can recognize a social road map because it often has a catchphrase or meme (like "splitting up") that packages up the whole experience. Even though it's stereotype, it still allows you to start communicating from common ground.