I'm not suggesting the parent doesn't love or care for the child, but if they could go back in time with the knowledge they have now, they would choose otherwise.
Also I'm not asking about myself, DS is the best thing that's ever happened to me, but his father often talks about how much he misses life and our relationship before him (which ordinarily I would call a normal reaction to being a first time parent, but he simultaneously acts like he can't be bothered and makes very little effort with DS which is where the context of the question comes from).