I don't think I received an usually large amount of presents as a kid but probably around age 10 I stopped enjoying it mostly. I didn't want more stuff and I didn't want to get stuff I didn't want, but I had to pretend to show gratitude and act like I enjoyed it when I had zero interest in it.

As a child I didn't know how to tell the adults to stop giving me presents I didn't want.

As an adult with a child now, it's still hard to stop people from giving you (and the child) stuff. For some people gift giving is for them, not the receiver.