The military is a weird place with its own unique culture. Although there are strict rules that apply to any and every MOS, there are certain things troops get away with, given the right settings.
Being an infantry rifleman, for example, grants certain permissions that allow you to get away with things that, if done by someone in another occupation specialty, wouldn't be tolerated.
1. Being dumb
While it's a stereotype for grunts to be stupid, it's rarely true. But in the rare event that a rifleman is dumb, it's expected, so you get a free pass. But, if you're not really dumb, don't make a habit of playing pretend or else you'll just be your battalion's own village idiot.
2. Being incompetent with office tools
If you get sent to the company office to make a copy of some paperwork but you're unfamiliar with how to use a copy machine, no one gets mad. Just expect to be treated like an idiot. (See point #1)
3. Going primal
The tribal mentality is encouraged in an infantry unit since the job is barbaric in nature. Higher-ups are surprisingly okay when the lower enlisted riflemen start acting like cavemen because it means they're getting in touch with a more primitive side that can make them more efficient.
Don't ask, don't tell is dead and the LGBT community is very much a part of the military now. But you kinda have to be a grunt to truly understand the relationship grunts have with homosexuality. They're not all gay, but sometimes you might think they lean that way.
When you spend all day, every day around other men, you learn to become comfortable enough with your sexuality to the degree that homoerotic behavior between heterosexual people is acceptable. In fact, the behavior is seen as humorous.