horrible fact: in the original nes super mario bros you can get "infinite" lives from some turtles. but there's NO such a thing as infinite lives, if you get more that 126,,,you die....alone...killed by your own greed.
Oh wait, you mean because Celestia got the infinite lives?
In Super Mario World 3, you can share your 1-ups with the other player. Who, if you're Mario, is your younger brother Luigi. That fit?
Immortal means you never die, not that you lived from the beginning of time.
Or, alternatively, she's immortal 'Highlander' style.
Either way, immortality didn't kick in until she was born, which was after the turtle park closed.
But Luna hasn't seen the turtle park.
So she thinks Celestia is a nasty creature?