Beyond Imagination

“How old are you?” A 6 years old boy asked me years ago. 

“You guess.” I replied.
“12 ?”
I tried to control myself not to laugh out loud. With a decent smile, I said: 
“Wrong. Keep guessing.” 
“O, you must be as old as my cousin, 16?” 
According to the given answers, I think my age is just beyond his imagination. 
“Not even close, I’m just ancient old.”
“Really? Old like dinosaur? Have you seen one?” 
I let him win, his imagination is far more beyond my estimation.