How old are you?

Simon's birthday is coming up soon, so I thought it would be good to teach him to answer the typical little kid question, "How old are you?"
The conversation went like this:
Me: Simon, your birthday is coming. You are going to be 2. Can you say "I'm 2?"
Simon: no.
Me: You are one and you are going to be 2. Can you say almost 2? When I say How old are you, you say "almost 2" ok? Simon, how old are you?
Simon: How old you, Mommy?
Me: I am 30.
Simon: NO! You are 2!
Me: No, I am not 2, I am 30. How old are you?
Simon: Not quite 2.