Brian, me too, happy memories, but you had to be 13yrs 9 months to be enrolled, you could attend from around 13 (from distant memory) and to take part in activities such as AEF's and shooting, summers camps et al, you had to be enrolled.
I spent a lot of happy times, did some great summer camps, including Malta one year, and did my A&B at Linton On Ouse. Our AEF flights in Chipmunks were from Finningley (now Robin Hood Airport) Linton, Church Fenton, and Leconfield, 3 of which are now defunct, only Linton remains as a flying station.
Great times, great friends, and a good grounding in discipline and citizenship.