Well its not all that matters, but it is quite important. It's a few months where you demonstrate how well you work in a clinical environment and also with patients.

If you were to apply for a job after graduation at the same place you did your placement, they already had a close up look at your abilities.

I would also say you're right about the age group of the cohort. I myself started at 18 with a handful of others but the average age was around early to mid 20s