Harry Potter was saved by a mother's love more than once. Harry may not of had his mother but he had a lot of comfort from mother like figures. Whenever Harry needed comfort it was always from a mother figure.
I never thought about it that way. I actually thought they were going to talk about there being an infinity symbol when I read the comment about an 8 in the Dark Mark. Also, did no one get the hermione can't draw reference from A Very Potter Musical?