My first one's baby book is complete. My second one's baby book is about half done. My last child's baby book is...well...I haven't bought it yet (she's 8yrs old). First two were 6 and 3 when we went to DisneyWorld and have vivid memories. My last child was 18 months and remembers nothing.
Our oldest "gets away" with a lot more than his sisters (because he's got special needs). I suppose the younger two find it "unfair" that I help him more with his homework or look the other way when he blurts out a swear word (he has Tourettes and sometimes can't control what comes out of his mouth). Unfortunately for them, I don't care if they feel it's unfair, they still need to do their own homework and I won't tolerate swear words out of THEIR mouths. I hold my son to the highest standard I think he can handle and I hold my daughters to the highest standard THEY can handle. Their highest standard is MUCH HIGHER than their brothers. So I guess a "lower standard" is something my oldest has that his younger sisters don't get...
In my case, it's kinda the opposite. I'm the oldest, my brother is 8yrs younger than me. Yes, I had a wonderful and privileged childhood, so I'm in no way complaining. When I was born and through out my early childhood, my parents were less well off (we've jokingly said my grandfather *owned* me until I was two because my parents couldn't afford to pay for ANYTHING). By the time my brother came along, my parents were doing quite well financially. When I went off to college (never to live at home again), my brother was still in elementary school. He spent the next few years flying first class and eating at fancy, expensive restaurants - same loving parents, totally different childhood experience. Not *better* than mine, just different.
I expect my kids will feel the same way when they're older. Three different people, three different childhood experiences. As long as they remember how loved and cared for they were, it doesn't matter if they felt it was totally "equal".