"My first few films were institutional comedies, and you're on pretty safe ground when you're dealing with an institution that vast numbers of people have experienced: college, summer camp, the military, the country club"

Harold Ramis is describing the truth that his very first couple of films were comedies that focused on institutions that many people have actually experienced. He is recommending that when making a comedy about an organization, it is a sure thing because lots of people can connect to it. He specifically mentions college, summer season camp, the military, and the country club as examples of organizations that many people have experienced. He indicates that these institutions supply a lot of comical product because of the shared experiences that people have with them. He is recommending that these organizations are an excellent source of comical product since of the familiarity that people have with them.