Boston Consulting Group Summer Intern interview questions

I first applied online and was contacted about a week later letting me know that I had been approved for the first round. I had a great experience in that first round interview. The front desk was warm and helpful, they had brought many full time staff to the event to answer questions, make everyone feel comfortable, and in general keep conversation going. The first day had two interviews which went very well. Both of those first day interviews were basic 45 minute interviews with the second half reserved for a case study. A few days later I was contacted by both associated with whom I spoke and they talked me through everything I could improve on. This was a great experience and I really felt like they cared about helping me. I made it to the second round and enjoyed a wonderful dinner with all the other potential interns the day before. The next day, the 2 interviews were of the same format but with much more senior employees. Unfortunately, I did not perform to my normal standards and was informed the next day that I was not selected. No hard feelings, I know I didn't deserve it based on my interview, and I will be back next year.