I was gone for conferences, 8 days over the last two weeks, and when I came back, my 5 year old son, whom is my responsibility (eat, sleep, etc), has become more attached to my wife. This really beg the question how much do kids really remember what we have done for them? it appears to be all short term memory. Certainly I hope the sacrifice we made for them now, they will somehow remember later in life, and appreciate it.
In some cases, what we need to do is actually raising them all we can, and then reminding them while they are growing up what we did for them. While some people say parents should not expect return from kids, and having kids and seeing them grow up are reward enough, I strongly disagree. If a kid I raised will not even appreciate what parents have done for him/her, how could this person growing up being a good man/woman? if a friend has done even 50% of what a parent has done for a kid, a person will be so grateful (eternally) and will be happy to repay in kind, why we should not expect the kids to feel the same way towards the parents?
of course, whether parents will accept such sacrifice from their kids in the future is a different story. but I think the society has evolved in such a way to make it almost immoral for a parent to accept a grownup child’s sacrifice, how ridiculous. This has evolution reason, historically, but should be seen as what it is now.