Why?
If you’re in the US, you should know this because if you want to apply for a passport, you’ll be required to provide information about your parents such as birth dates and places. If you’re divorced, you will have to provide the same info along with marriage and divorce date, even if it was decades ago. So if you have access to that info, make sure you record it somewhere safe for Future use.
If you’re not in the US, you should know because this information can be difficult for people to get if they never knew one or both parents, or have a bad/non-relationship with them. Or if they had a contentious divorce or an abusive partner. Which is another reason why just leaving the country can be difficult for people who are already marginalized.
The US is not only quit populous, our huge footprint and lack of government centralization causes a lot of stupid shit like using bills for proof of residence. Imagine tying 100s of thousands of databases together so the federal government can pull all info on a citizen.
BTW, this is exactly what Palantir is accomplishing and we should be screaming about it.
My wife had to sent utility bills with her name and our address on it to immigration to prove she didn’t marry for the green card and we’re actually living together. And don’t start me on our immigration system, totally and purposefully broken.