My military experience is just slightly more than fuck-all (MEPS washed me out), and I can tell you for the stage you are at right now (recruitment), this is the best advice you can receive. My USAF recuiter "advised" me to my face to withhold medical history (that I have asthma), then when I found evidence of the withheld condition to satisfy the MEPS inquiry into something else from way early on in my childhood, the recruiter advised me to withhold that and have my parents sign and notarize a statement saying it doesn't exist (I had a hard copy from the hospital microfiche in my hand that I placed on his desk) or submit to the MEPS and see what happens. I went for the latter. In this stage you have to think about no one else but yourself, and you have to stay 4 steps ahead. Assuming I would have lied about the document and made it through boot, my money is that the DSS (or whoever they have now that investigates and grants security clearances) would have easily found my ruse, denied me my clearance necessary for the AFSC I wanted (computer network security) and I would have been well and truly fucked for 4 years, or in a brig in Leavenworth. For the recruiting stage at least, make sure it's all about YOU. Once you get in that parade formation at the MEPS and swear in the game changes, but until that happens you're on your own.