First, you have this little baby who you have no idea what to do with (let’s not even talk about how it feels to be pregnant). This baby takes all of who you are, and I do mean all of you. You eat, sleep, and breathe baby. Otherwise, if you didn’t, the baby would not fair well.
Then, after you baby gets older, some people decide to have another. Not all, but some. And you do it all over again, still loving and doting on your first albeit maybe a little less than before because now you are eating, sleeping, and breathing baby AND other child.
It does help that usually at this point, your oldest doesn’t know too much differently. These two grow together and figure out how to become siblings, and before you know it, you either add another one or two (or in other cases more). Or you suddenly realize that your baby that you didn’t know what do with in the beginning is now a very competent 8 year old and you don’t know how to do this. Now you are eating, sleeping, and breathing the school-age years. Because if you didn’t this child of yours wouldn’t fair well.
But it’s weird.