It's kind of hard to ignore how much a child can resemble a parent sometimes. They often mimic their parents, idolize their parents and want to be like them at an early age. So it's not "unhealthy", necessarily, for your offspring to be similar to you. It's very natural, in fact. And in a way they ARE undeniably an "extension of yourself"; they share like 50% of your DNA after all. Of course extension of self does not mean "little clone who needs to be pushed to forever remain a little clone", and that's where some parents fail.