I also go completely overboard, just like my mom did/does. I think it's genetic! I too love tons and tons of gifts under the tree.
I think it's really hard not to since I shop little by little, and I don't realize how much I've purchased by Christmas.
I do think it is a bit out of control since DD is the only child and only grandchild for my parents. Hopefully next year we will tone down a bit.