Don't know why I'm thinking about this, probably just hormonal ,but do you have any fond memories or experiences from your childhood that your children won't experience in theirs?
For me, its my cousins. Both my parents come from large families so I've a heap of cousins on both sides. I was quite close to some growing up and now they're married and having their own children it's sweet to watch their kids grow up.
I'm an only child and my OH has two siblings, neither of which have interest in having kids, so it's possible our future children will have no cousins, or very few, which makes me a bit sad. There's something about shared family experiences and memories that I love.
Anyone else like to share?