Two things were painful for my S - one was getting into schools near the top of his list but not being able to afford them, and one was getting waitlisted/rejected from a school when kids with much lower stats got accepted.
getting rejected and having other people at your school get accepted when they are clearly on a lower academic level than you.
Kids with good/great HS records get into good schools, but to get one’s heart set on any particular uber elite school is, unfortunately, just asking for pain and disappointment. There is no real understanding of how admissions works at any of these schools. Acceptance posts on these boards shows lots of kids who were denied by every ivy except Yale, or got into Stanford but not Georgetown, or got into MIT but not Wash U, or got into everywhere with stats quite a bit below many who got rejected from most or all of the uber elites. The sacrifices that so many of these kids make in order to be seen in the best possible light by ad coms is unhealthy, especially when so few did it to go to the exact same schools just a generation ago. A good education remains an absolutely wonderful and important thing, but I think there is a tendency to imbue some of these schools with qualities that they don’t possess. Big goals and dreams are great, but I think it’s really important for us as parents to help our kids understand what a ridiculous game the competitive college admissions process has become. The important thing is the trying, not some ad com deciding that another really bright, hardworking 17 year old is going to add more to that school than your kid. Most of us live about another 60 years after college and most of us have jobs that ask us to prove ourselves worthy day after day, and they really don’t care if you’re a valuable employee from Harvard or a valuable employee from State Flagship.