Celebrating the person who brought you into the world,
Some of us are lucky enough to have parents who made a conscious decision to have children, worked out what it would cost them, understood that it was a responsibility and a commitment, and decided that the costs were worth it. Some people have parents who fucked and forgot the pill (or whatever) and decided that keeping the child was the path of least resistance. For those of us in the first category, one day a year per parent is nowhere near enough - we owe our parents a lot for the advantages that we had early on that let us succeed later in life. For people at the opposite extreme, even one day can seem like an insult.
wiped your ass for you and taught you right from wrong, for one day per year,
You don't need to do any of that to qualify as a mother, you just need to make it to childbirth. If you're in the first category that I described, then please do remember to appreciate your parents, but please also remember that those advantages that you're thanking your parents for giving you (teaching you right from wrong, as you say, and hopefully teaching you to value education and how to be happy) are not universal.
Remember, occasionally, just how lucky you are. If you're born in an industrialised society, in a stable family, with supportive parents, then that gives you a huge advantage in life.