A Better Insight (Maybe)
I think what a lot of younger siblings and parents don't understand at the time is. There's no guide that appears out of nowhere to tell an older sibling "How To Be" an older sibling. Especially when there's a huge age gap. We get thrown all this extra stuff but still have to map out our way on our own without anyone to help us.
Right now my sister is 13. Very opinionated, challenges and questions what I say, rebeling and talking back a little. The works...
It can be challenging a lot of the time... It's like you don't know when to help and when to let go and wash your hands from it all. Lots of feeling like you're walking on egg-shells, because you don't know when the timebomb is going to tick.
I don't think younger siblings (in general) at the time of pre-teens and maybe teen years, don't understand how difficult it is to be the older one. (not saying it's peachy being the youngest either but...)
When your first born parents usually don't know how to parent. Parents are still in their rough way adjusting to parenthood (because there's no magic book that gives them all knowledge). They learn and grow and react in more of a raw way, than they would do once the 2nd child comes along. So the younger child's path might be paved smoother. (not counting for the siblings that are in the older one's shadow though.)
And to us older one's, when you are born... we start like how the parents were brainless cold mindless fools lol) and we have to roughly learn from our mistakes. Sadly at your expense.
ESPECIALLY if we (at the time) are in our "teenage years".
Being 1st, we were probably spoiled, got all the attention, had no responsibilites, etc. and then your lovely faces came along lol. Immediately when you enter this world it all changes. We get the "you should be more responsible talk, act your age talk", we get more chores, get pressured to be good role models, get cast aside more than we're used to (if not a lot).
It's like we're expected from EVERYONE to automatically know how to be this given role and in reality we have no freaking clue!
Younger siblings can get away with so much more stuff than we could. Which is a pain (do you know how many spankings I would've NOT had if I were the youngest, and I wasn't even a bad kid.)
And sometimes we might "overstep" our boundaries as older siblings. It's a see-saw of what's mom/dad-like and older sibling-like. At first we don't know where the boundaries are or how to deal and go about something.
As the oldest (of course) everytime I'm "not perfect" I get told up, down, sideways and every other direction. Yet, my sister doesn't get any of it because "she's growing and finding her way, or it's ok." At her age when I was "growing, and finding my way" I STILL was put in my place every which direction that exists. But that's the way it goes. *shrugs* It goes with the title I guess.
*~That's my personal view as an older sister. I would really like to know a younger siblings guide of what they go through.~*