"I Know"

So I go pick Faith up from Kathleen's house (her babysitter) and us adults are talking for a minute. She tells me that Faith was playing with Lynkon, who's about 6 months old. He really really likes to watch her & play with her and always laughs when she talks & plays with him. Well, on this particular day she's playing with him & he's laughing and Kathleen says "Lynkon really likes to watch you, he thinks you're pretty" and my sweet, modest daughter's response? "I know!" and keeps playing with him! Of course, in her defense she also says "I know" when you say, "ooh, we're running late" or "It's time for bed" or, my favorite, "Faith, you're silly". "I know!" So, here she is, 13 days from being 2 and she already knows everthing! I thought that didn't happen until they were teenagers?