We all know that gaining rank & authority really just means that now you are someone who can be Held Responsible for things that go catastrophically wrong.
And soon after realizing that, you also realize that, as the junior-most person on the downslope of the responsibility chain, you will be the first one under the bus when that catastrophe happens!
When you’re younger, getting in “youthful trouble” might have seemed daunting at the time (depending on the trouble you were in, I guess) but when you look back in retrospect, you realize that it probably wasn’t a big deal. The consequences for young, irresponsible trouble probably just affected your immediate self, although I’m sure we all knew some over-achievers out there.
But then you get older and gain some responsibility, and you realize that consequences can include a lot more than just yourself. In fact, you can even get into trouble for things that other people did, and you were just the person who was supposed to be in charge of them at the time.
I always felt like that first big promotion into the world of the NCO or junior officer was like that time when you turn 18, and you feel like you can do anything, and then you realize that this time, you can now be “tried as an adult”.