4 year old's decision to de-clutter

Right before Christmas, my soon to be 5 year old kept telling me that she needed lots of toys for Christmas.  I told her each time that she didn't NEED lots of toys, she only needed a little bit.  Then some people from church gave her a bunch of pretty dresses that their girls had outgrown, and my daughter, who was very excited about getting so many pretty dresses, kept asking me why they gave the dresses to her.  I told her that they didn't need them anymore so they gave them to her.  After having the previous conversations several times, and after feeling overwhelmed by all the toys when they're scattered all over the kids room, something seemed to click in her mind.  She told me that she didn't need all those toys and there were too many.  So she went through her stuff voluntarily and filled this whole diaper box full of toys she didn't need anymore.  Then she came with us to Good Will and she helped us hand the box to the donation collection people (we had to help her since the box was a bit too large and heavy for her).  I was so proud of her!  And she kept smiling to herself, I could tell she felt good about it.