Because you only have it in your mind that you want to serve your country. You don't seem to know what an army entails, and you don't seem to even have the skills to deal and rid of your sensory issues, or to be independent and try to do your own research on it, instead of asking us questions all the time? You don't seem to understand why being in the army would be a problem for someone with sensory issues.
Army recruits are very independent. Every man for himself. You have to learn how to live a harsh life. It's not just sitting in giant tents and camping together, it's heavy equipment, running with it through any weather, having the people in charge shouting at you, and you cannot take it personally. Shining your boots every day, dealing with the food they give you, even if you don't like the texture (unless you have allergies). They won't tolerate a fussy eater.
You get up at 5am, you run and run until you're tired, and then you're on the battlefront trying to save your best friends life who's just been shot.
Women and children are panicking, screaming for their family member who's been blown up by a mine, when they were just playing a game of football.
Could you seriously deal with all that?
You don't get to call home to your friends and family when you want. You get it when they tell you you can. You're out there on your own, with the people there to make friends with, but you can't get close to them, because they're likely to die.
What if you get shot in the leg, and have to have it amputated? Could you deal with being in a wheelchair for the rest of your life?
How about being shot in the spine, and being paralyzed?
You have to consider all these factors, because I really don't think you're taking the army seriously.
I have a cousin in the army, and a good friend who's in the military police, it's no joke.
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Your Aspie score: 187 of 200
Your neurotypical (non-autistic) score: 25 of 200
AQ: 43
Empathy Quotient: 8
I have ASD, ADHD, Hypermobility Syndrome.