How long do doctors have to go away to school?

In the UK after finishing school at 18 or 19, you need to go to a University with a Medical School (not all universities have them) and teaching hospital. You will then spend 5 years learning to be a doctor, (after this you are qualified as a General Practitioner GP).

Following this you may spend further time (several years) working in teaching hospitals if you want to become a hospital doctor/registrar/consultant.

To be a good doctor you need to keep your skills up to date throughout your working life so if you are a doctor you actually keep learning all your life.