I'm big now, Mom

Benjamin has been telling us now that he is three, he's bigger. He actually told me that he felt taller when he woke up the day of his birthday!
Today he went to the doctor for his 3 year check up. Dr. Guru had him jump on one foot, walk on his heels, and do some other things. Now, he's officially BIG.
He's helped pick up today - he did boss his sister, which caused a few arguments! He does a lot now that he's BIG.
As we were getting ready for bed, we were putting stickers on his door.
Background: In an attempt to establish a routine, Jeremy and I decided to give Ben stickers every night on a chart. He gets stickers for picking up toys, brushing teeth, reading, sleeping in his own bed, and not getting time outs. The chart was a great idea, but he didn't get that the stickers went in the neat columns that I made under the cute pictures. He filled the page with stickers, and then his door. Now, he has a beautifully stained door covered with Clifford, smile faces, jackolanterns, Spiderman, you name it.
Anyway, he put his stickers on his door, and turned to turn out his light. I'm pretty sure yesterday he couldn't reach that light! I said, "Ben, thank you for turning that out."
His reply: "I'm big now, Mom."

Not sure I can handle having a "preschool aged" child!