From what I have heard and experienced undergrad and post grad will be very different experiences. One of the most unique experiences of college undergrad is the dorm system. You build a lot of close connections with the people around you just because you see them all the time, and also other undergrads will open up to you more easily just given their age. Meetings at 10pm in the evening, stressing over exams together in the library at 4 in the morning, heading to parties and other events together, You won’t get that kind of experience post grad because people mainly live off campus and will more career oriented.