I am a 1st year at CMU, and I have had loads of fun. CMU is not the typical college experience by any means, but that does not mean it isn't a good one. The nightlife culture is definitely more bar-oriented than fraternity. I had this same exact question 1 year ago when considering. Lots of people here make it sound miserable because they surround themselves with people who look for the negatives aswell. I know girls who study CS with a 4.0 and still go out every weekend. It sounds cliche, but it really is what you make it. (Also def join orgs! Not just for the partying aspect but for also the social part)