Anyone who has seen How I Met Your Mother knows that the characters in the show can teach us all a few things about love, sex, and relationships. While this may be through their many mistakes, sometimes their "theories" can actually be backed up in real life, and some, with hilarious accuracy:

The Cheerleader Effect

The Cheerleader Effect occurs when a group of men or women appear to be more attractive collectively than they are individually. This explains the phenomenon of every guy wanting a cheerleader, or in my case, thinking every member of my favorite band looked like a model. This isn't just a shallow TV show thing, either. Five different experiments by the University of California, San Diego’s department of psychology give a scientific basis for this theory. Basically, when our brains view certain sets of objects (or people) we make generalizations based on our pre-existing expectations for those objects. This establishes a hasty opinion on the entire group from a quick glimpse and a mental association, so if you think that soccer players tend to be hot (and let's face it, they are) you will interpret most groups of soccer players to be attractive.

The Mermaid Theory

The Mermaid Theory is one that we all want to shrug off as crazy, but deep down we can all think back to at least one instance where this is true. Have you ever had a friend or just a simple acquaintance hang around you so much that you suddenly start thinking they're attractive? Within our daily lives, we find things that are familiar to be more appealing, so it makes sense that attraction would work the same way. This theory says that if you have a friend or coworker of the sex that you're attracted to, it's only a matter of time before they go from manatee to mermaid!

The Hot/Crazy Scale

The Hot/Crazy Scale is a theory that we should all live by and honor. This law states that in a relationship, a person is allowed to be absolutely insane if they are equally hot or hotter than they are crazy. Barney Stinson explains that in an ideal relationship, your significant other's hotness should be above the diagonal line, indicating that they are hotter than they are crazy. I mean, haven't we all been really attracted to someone even if they do leave our phone with 27 missed calls, 40 texts, and a few strongly-worded voicemails?

The Reacher/Settler Theory

The Reacher/Settler Theory can be a touchy subject for many if they're currently in a relationship. Ideally, we would all find someone who we see as our equal, but in reality the world is full of reachers; people who go out of their way to pursue someone out of their league, and settlers; people who could do much better but like the stability and gratification they get being with someone beneath them. As far as I know, I've always been a settler. Right?

Graduation Goggles

As Robin explains, Graduation Goggles work just as they did before high school graduation. They fill you with nostalgia and a longing to stay just a little longer. In a relationship, this happens right before you're about to break up with someone. All of his/her annoying habits become cute quirks that you adore, and you're suddenly attracted to that person like you were at the beginning of the relationship. Don't fall for it.

The Dobler/Dahmer Effect

The Dobler/Dahmer Effect is my personal favorite. This theory reflects on the basic premise of attraction and rejection. It states that if a person reciprocates the affections of their admirer, a grand gesture will work, and they will be a Dobler (much like the romantic Lloyd Dobler from the 80s classic Say Anything). However, if a person does not reciprocate one's affection, things get really creepy and weird. That person is automatically labeled a Dahmer (based on the serial killer Jeffery Dahmer) and will never have another shot at wooing the other person. Yeah...because that kid who left you love notes on your locker in 7th grade was "totally obsessed" with you.