If there is any selfless feeling in this world, it must be maternal love. The reason why you don't say it's paternal love is because, to some extent, your mother is a direct physical person, and your father may not understand this feeling, because in real life, even if a family has many bad things, this mother is usually not too hateful, and domestic violence is more often done by his father. So maternal love is the greatest and most selfless love in the world. Your mother loves you unconditionally and doesn't need you to be excellent.
Because in the mother's eyes, sons and daughters are always the best, others may have other achievements, but a mother will not care so much, just want her children to live well, at least better than herself. If they are worse off than themselves, try to help their children. If you live better than yourself, parents will feel very gratified and feel that it is a happy thing for their children to be better than themselves. At least, I don't have to go my own way, and I don't have to eat the children I have eaten. The hard-earned money I spent before is worth the price.
Remember that no one will love you selflessly, even your current partner. You two were together because you were nice to each other, and then the other side was nice to you. But at first, your mother loved you, not because you were kind to each other, but because you were his child. She was kind to you unconditionally and didn't ask for anything in return, so when she has the ability, she must take care of herself. Parents still have to do what they can, because the love between mom and dad will never end, but this does not prevent us from loving our parents.