My tuppence worth and directed towards the original poster. Firstly to ensure I am not accused of being a 16 year old wannabe (but I am still fresh faced

); I was an IGDT instructor for a good few years at Halton.
Peter,
By your own admission you joined an organisation that at best you were unsure about the final role you would undertake. You clearly have a drama with commitment and to stack after 1 week demonstrates a serious lack of determination.
I fail to understand how anyone can pack a new lifestyle in after less than 7 days of trying. It certainly wasn't "hell". The phys is most definately not at "a high level".
I would be interested to know what you thought was actually going to happen at Halton.
The system there from an instructor's point of view when a recruit asks to leave so early is complex. Initially we are briefed to try and influence you to give it a good bash and stay a few more weeks. I would suggest that a goodly number of those who did so actually realised what was what and did complete the course.
To manage to leave after such a short time matey means you were identified as a person who is not suited to service life. This opinion can be reached in many ways:
Perhaps you had no aptitude (just couldn't cope)
Perhaps you got homesick
Perhaps you were the course wnaker who pissed everbody off so much in the first week that the staff could tell you were going to be a drama and were glad to push forward your application
I agree with whoever said it before; you are probably best out of the RAF as you don't really appreciate what is required of you nor do you have the determination to push past the first hurdle.
I wish you all the best for your future career.
Regards
ss
PS That was the the polite version. I can sum it up in one sentence should you require it.