I believe people are about emotions. Owning things, reaching the “next levels” at work, traveling will not provide you the same amount of emotions. Parenthood opens wide access to new set of different emotions — you can not feel unless you are a parent. Some of them are awesome, some are bad, but in general in most cases positive are dominating. By having a kid your priorities change by 360. You have somebody you love unconditionally, who can not survive (in first few years) without you. These feeling make having a child so special IMO.