Loving their sorority and/or fraternity or is it just silly?

I know this lady whose well into her 40's (years old) a member of a black sorority and acts as if she just joined yesterday. Most of the clothing is the sorority colors, she stated she has painted most of her rooms in her house the sorority color (which is her choice). She wears the paraphenalia to work (which a previous administrator asked her to cool off from wearing the paraphenalia). Sometimes, she looks as if she is going to s step show.When I first met her, I asked her did she just become a member and I was shocked to find out that she had been a member for 15 years. Most of the time, she sings the sorority chants and talks about her sorority or the sisters in her sorority. Oh, and don't let someone she works with belong to another sorority she tries to compete and debate about the sororities. Just for discussion, what do you think of people like this? Do they think that the sorority or fraternity they are involved in define who they are? Do you know anyone like this?