The thing about Harvard and other Ivies is that, while it’s extremely difficult to get admitted to them, once you are in they do everything they can to make sure you don’t flunk out or drop out. It’s a version of what I call the “glass floor” effect: once the powers-that-be have invested in your success, they’ll keep giving you chance after chance and free pass after free pass no matter how badly you screw up (at least until the screw-up is so bad it makes the national news, and sometimes not even then).