What you describe is not uncommon, though parents who are interested in their kids seems to be the exception rather than the rule.
I have always said from the time I was a teenager myself, that condoms were invented for sex partners who have no real interest in raising children, but who have children anyway and then bit*ch about the price of condoms being the reason they never bought any condoms.
For many parents, having children is what results when you have unprotected sex and producing unwanted children or accidental children is what results when you have not received any meaningful sex education at a time in your life when you were sexually active as an adolescent or young adult.
What you needed to experience from that restaurant visit was simply the difference... you needed to see the difference between what you witnessed and what you personally experienced. Now that you know the difference, don't repeat your parent's mistake by not being engaged with your children for your whole lives together, even after your kids have moved out on their own.
