He knows his birthday is coming

We were in the van on the way to the library and Charlie was repeating whyyyy? Wh-hhy-ee? and he was really playing with the word. He kept stretching out different sounds and parts, different inflections, etc. Melody kept answering 'Because!' 'Because!'

Then she wanted to know, "Why does Charlie keep saying 'why'?"

"Because he's practicing for Two."