Undergraduates often focus on doing more cases when the real issue is a specific skill: weak structuring, slow math, poor synthesis or not listening closely to the interviewer. Repetition alone does not fix the wrong problem.

Another common mistake is trying to sound 'consulting-like' instead of thinking clearly. Overly memorized frameworks and jargon can make the answer less responsive to the actual client objective.

After each mock, write down the one or two moments where the case broke down. Then drill that skill separately before doing another full case.

Your goal is not to eliminate every mistake before interviewing. It is to build a repeatable process, recover when something goes wrong and show that your reasoning remains structured under pressure. For more detail, see the case interview guide.

After ten cases, I would want to know whether the mistakes are actually different each time or the same one repeating.

What helped me was separating the weak skill from the full case. Doing more complete cases wasn't fixing the same mistake.