This question caught my eye because, when I saw it, I realized I don't remember my first Mother's Day. The story will be less interesting to others than it is to me (of course), but I have no recollection of the day for three reasons: 1) When my mother was alive my siblings and I always put together a "thing" at my mother's house. So, with my mother's children and grandchildren all focusing on her, I didn't think much about myself; 2) My first child is adopted and had been placed in our home for adoption years before the finalization, so when the finalization made me "legally" a mother (years after taking on the role while not being "officially" a mother) in January, it was pretty anti-climactic by Mother's Day; and 3) I had had a 20-week miscarriage "situation" a couple of months before Mother's Day, and maybe I was tuning it out for that reason.
So, my entrance into being a mother was a kind of muddy one. The Mother's Day after the first one I was expecting another baby and not wanting to think much of being a mother (for earlier reasons). By this time, the son who had been placed with me as an infant was now four (a "big kid"). The following year my baby was all here, my first son was five and kindergarten. I recall he gave me a kindergarten-made gift for Mother's Day - and that's the very first Mother's Day (for me) that I recall.
I may as well throw in that I went on to have a daughter three years after that.
The Mother's Day I most remember is the one that occurred the first year all three kids were able to put together a day/gifts without their father's help. They put together the most beautiful, elegant, day - and selected gifts for me that were exactly the kinds of things I use/like. Seeing the three of them scoot around and "be up to" their "secret dealings" before bringing out what they'd put together was so nice, because I saw how close they all were. I think THAT is the Mother's Day I will always remember most. :)