You wouldn't catch me working on those to save my fucking life. The two things to this day that still scare the fuck out of me are hearing an airstrike and the "INCOMING INCOMING INCOMING" from a C-Ram before it plays the symphony of hell.
Real shit. You have to be trained in hand to hand, all the weapons you'll have in the field, a cursory understanding of other weapons, local customs, how to nig rig at the drop of a hat, basic field medicine, radio protocols, where to buy black market stuff, what stuff to get sent to you from people back home (silly string saved our asses lol), and a myriad of other things that I can't even think of off the top of my head.
Factor that in with the idea that at any second an IED can hit the Humvee you're riding in and fucking melt you alive into the seat, or somebody could detonate a suicide vest or cell phone bomb every time you're at a marketplace or raiding a house, or a firefight could break out literally at any second.
And the shitty thing is, there's NOTHING you can do to prep your mind for that. Anybody who says it got easier is just trying to sound like a badass. Every single time something popped off, your legs would turn into spaghetti, your stomach would drop into your asshole, your hands would shake, your gear would weigh 300 pounds and your mind is shrieking "I don't want to die I don't want to die please God don't let me die oh my God I'm going to die"
And that's why they run you so hard and break you in BT. Your drill Sergeant is literally factory resetting the bitch out of you. You will still have that cowardly scared shitless freak out, but because of getting the instructions knocked into you so many times you'll go into autopilot and just let Betty chatter.
Lol, I nicknamed my rifle "Betty" and my sidearm "Veronica" like the Archie girls. I was so fucking bummed they wouldn't let me take them home, even if they were deactivated