But Why?

Eden at Target today:
Eden: Can I sit there?
Mom: No, we're sitting here
Eden: But why?
Mom: Because we'll block the door there.
Eden: But why?
Mom: Because the door is right there and people need to get out
Eden: But why?
Mom: Because I said so!
Eden: But why?
Eden has definitely entered into the but why phase of life. I know that it's a normal progression but it's wearing me out. All of the sudden Mike and I are realizing that the response that our parents always gave us, "because I said so", makes a lot of sense- just not to her.