I applied to Cambridge twice. First to Christ's, then to St. John's.

In my first interview, they asked about capacitors. That topic had been dropped from the IB Physics syllabus the same year I started the course. I hadn't studied it. There's a reasonable case for calling that bad luck, and maybe it was. But I didn't find that framing particularly useful.

Going Beyond the Syllabus

After finishing IB with a 45, I decided to apply again. This time I studied general physics — university-level physics, the kind taught in first and second year undergraduate courses. Halliday, calculus-based mechanics, differential equations. Things that sit well outside what any school syllabus requires.

In my second interview at St. John's, one of the problems needed exactly that. I don't think that's a coincidence, but more importantly, I don't think it matters whether it is or not. Cambridge interviewers are not pulling from the IB or A-Level syllabus. They're seeing how far your thinking goes. If you've only prepared to the edge of your school curriculum, that edge will show.

The point is simple: if you're aiming for 100%, train for 120.

What Mock Interviews Are Actually For

Most students use mock interviews to learn things. A tutor explains a concept they didn't know, they write it down, they leave feeling like progress was made. I think this is the wrong way to use them.

Learning belongs in your own time. A mock interview is not the place for it. What you actually need to practise — and what you can only practise by doing — is thinking out loud under pressure. Saying what you're trying and why, even when you're not sure. Staying organised when a question goes somewhere unexpected. Not going silent.

For a lot of students there's also the English. Explaining mathematical and physics knowledge clearly in your second language, in front of someone, in real time, is its own skill.

None of this improves from being given better content. It improves from doing it badly, seeing what that looks like, and adjusting. Mock interviews are for fixing habits, not filling gaps.

What Interviewers Are Actually Watching

Cambridge interviewers aren't checking whether you've covered the right material. They're watching how you think when you hit the edge of what you know. That's a different thing to prepare for, and most people don't prepare for it directly.

There's always some luck in the process — the questions they ask, the dynamic in the room. You can't control any of that. What you can do is prepare thoroughly enough that luck has less room to matter.