Whereas a mother's love is able to keep the mother herself going in King's Quest VII, it is also what keeps the child going, as Earthbound alludes to.
Ness' mother, who has no name, will regularly feed Ness' favorite food and give him a place to sleep so that he can be fully rejuvenated for the next fight. It's the simple stuff that counts, am I right?
Better yet, if Ness doesn't come by and say hello to his mother enough, either through visiting or a by calling her, he will eventually become homesick. This can occasionally cause him to miss a turn in battle, so it just goes to show that a child needs their mother in order to keep enduring the hard times.
Without our mothers, we aren't a strong as we should be. They can do a world of good for all of us, so just remember, if your mother makes you some food, be sure to thank her for it afterwards.