Me: "That nightgown is getting too small for you"
Reegs (age 5):  "That's because I'm getting bigger.  I'm almost seventeen."
Me: "Orly?"
Reegs:   "Yeah.  *counting* five... six... seven...eight,  nine,ten,eleventwelvethirteenfourteenfifteensixteenseventeen.  See? I'm  almost seventeen."