I take so many for a few reasons. One, I think they are crazy cute and want to take pictures and videos when I see them doing cute things. Two, my 4 year old loves looking at them... she wants to see videos of herself all the time, and cracks up seeing herself as a baby.
Three, I don't do a baby book but want to be able to remember how they were at these ages when they are older. It is already trippy/fun to look at pictures and videos of my daughter at 4 months and compare them to her baby brother now. It is fun to watch old videos and see the first bits and pieces of the kid I love now.
99% of the pictures and videos haven't been looked at by anyone but me and my daughter, but I am SO glad I have them.