Garrett's Greeting Turns Sad

One of the highlights of my work day is when I go to pick up the boys from their day care center. I usually gather up Garrett first, and I get a huge greeting from him. When Garrett first sees me, he gives a big smile, makes a guttural laugh, and comes charging me with his arms stretched out. He hugs me and grabs at the hair at the back of my neck with his little hands in a loving gesture. Over the past few pick ups, this lovely greeting then turns immediately to a "throw himself on the floor and cry and out" demonstration. I wonder exactly what he is saying. "I love you, Mom!" Quickly followed by him trying to tell me how hard it is to switch from two naps to one a day, or how exhausted he is from toddling all day. His sadness is usually short lived and I assume has more to do with Garrett exerting some of his own independent feelings.