Papote,
Yeah, get use to that sadly enough. Doesn't look like it's getting better anytime soon. But on the bright side you are joining the best ranks around so to that I say congrats! Mest is mission essential skills training which is a long fancy term for on the job training after technical school. Each AFSC has a certain amount of days allotted for MEST. Also I was reading previous responses and noticed people talking about commissioning. AMS is no longer available as everyone now goes to OTS for officer training. AMS used to be a shorter officer training for prior national guard guys, six weeks long instead of the eight weeks of OTS. By the way, if you do consider commissioning my opinion is to start enlisted first, do a good job and they will give you a waiver for your age. Easy as that! Good luck!