"Daddy, I'm 5 and a half years old!"
"Yes you are! How old do you think daddy is?"
"Uhm... four."
"Four years old?"
"Yesh!"
"So I'm younger than you?!"
"No, daddy, you're four ADULT years old."
"Ah yes, silly me."
Honestly, she's got a point. Adult years hit different from kid years.