It's not easy transitioning between early starts, long hours, separation, limited communications, discipline, physically & mentally demanding days to restful lie-ins, relaxing drinks in the pub with friends & loved-ones, eating as much as you like and virtually no phys, no-one shouting anything beyond 'dinner's ready', and then, click. Back in the room: early starts, long hours, separation, limited communications, discipline, physically & mentally demanding days...
After every leave period there's a sharp rise in voluntary withdrawals from the service. For those maybe with a partner, or children or limited previous experience of separation from their loved ones, particularly those under age 20, it's all too much and they quit. The mental strain upon return to the 'rigours' of training is simply too much.
Generally, about a month after the end of a leave period, AFCOs are toppers with people saying 'I made a mistake'. To which the reply is usually 'You did. Come back in a year or two'.
I'm glad I didn't have a break when I went through, but then it could be worse; the current batch are coming to the end of 4 weeks off! Some of them will have spent more of their career on leave than at work.