TOFO - I resemble that remark!
For those mentioning the pension abatement - the way I see it is if you are going back in and getting the same pay as when you left then yes, you will lose your pension (full abatement). If you are going back in onto a lower pay than when you left, your pension continues but only enough to 'top-up' to the amount you were getting previously. I believe that has always been the case for rejoining HM forces (or civil service?). Interestingly, the latest pension scheme has changed this so a pension you earn from here on on the new scheme will not be affected by later additional service (as I understand). If you are rejoining just for the money, I think you may be missing the point of being able to do the job you want to and the other benefits of service life (such as they are - no rose tinted specs here).