And upfront, they were all treated differently. Not by fault, mind you, but just by happenstance. You probably didn't fawn so much over the second, and even less on the third. Not because they are less special, but more because you had a sense of what you are doing. You came into the second and third child with a battery of things to try because you tried some on your first child.
You are probably less strict with the youngest child and worry a bit more over the oldest.
Plus you and your spouse (or whoever) have aged and matured with time, so each child gets to know a slightly different version of you, your spouse, your parents and family. The more spaced out your children are, the more this will become so.
Well sure. Notice I said homeschooling and preventing most contact (which actually makes homeschooling redundant).
Kids likely won't turn out the same even with the exact same environmental inputs, but I'm just pointing out that we often vastly over estimate our ability to control those environmental inputs in the first place, so the point is somewhat moot.