欣
=
斤
+
欠
:
It's Marie Curie's (xi) birthday and someone sings her happy (欣) birthday in front of the encampment ((e)n1). The person gives Marie Curie a barbell (斤) as her birthday present, which makes Marie very happy (欣). The person attached an IOU note (欠) to the barbell though; Marie will have to pay for the barbell eventually.