It may be special treats found in their refrigerator each time we visited. Making macaroni necklaces. Teaching us to crochet. Allowing us to do what our parents never did. The always-available baby-sitting provided. The list can go on forever about the nurturing of our grandmothers and the importance of that in our individual development, as well as their place in our families.
Even more interesting is a new study based on computer simulations that supports the "grandmother hypothesis:" That we couldn't have done it without them!
The theory is that humans evolved longer adult lives than apes because grandmothers helped feed their grandchildren over some 24,000 to 60,000 years of development.