Having been offered and firmly accepted a place at Cambridge, I quite often feel scared that, if I meet my offer and go there, both the workload and the difficulty level will be too much for me and I won't be able to hack it. But I'm sure 99% of offer holders feel exactly the same way, and if we were all put off going because of fears we couldn't cope, Oxbridge would have no students! I'm sure everyone who applies is fully aware of how hard it will be, and in a lot of cases, the challenge is what makes people want to go there. At the end of the day, the admissions tutors only offer places to those they feel are good enough to handle it, and they're probably right most of the time. The majority of those who apply and are accepted into Oxbridge are not only intelligent, but also very hard-working and good at time management. Whilst there will be some people who get there and realise that actually they were right and they can't do it, I'd say Oxbridge's extremely low drop-out rate indicates that this is pretty rare and that most people do learn to adjust.