The psychology concept that I believe I will still remember and put to use in five years are the primary emotions. Everyone has seven primary emotions that are believed to be universally recognizable across multiple cultures. These seven primary emotions are happiness, disgust, sadness, fear, surprise, content, and anger. Happiness is believed to be the most easily identifiable emotion whereas emotions like disgust are the hardest. These seven emotions are extremely basic and when they are combined they form all other emotions. Everyone has an imbedded ability to distinguish these emotions no matter what gender, race, or age the person giving the emotions is.
Personally, being in a sorority has helped me a ton when it has come to recognizing the primary emotions. With there being over eighty members in it, being able to pick up on others' emotions is critical in keeping a house from having drama. When a girl walks into the house it helps when you're able to recognize her basic feelings and then being able to react accordingly. You want to celebrate with your sisters when they are happy and pick them up when they are sad. If you're oblivious to how everyone around you is feeling it could potentially lead to even more hurt feelings.