It's very simple.
A cat has nine lives, I'm sure we can meow all agree on that simple fact.
If we were to display how many lives an unscathed cat has, it would have to be x9. To say x10 would be disingenuous, as we all know a cat has but 9 lives.
9) So at the start a cat has Lives x9
8) If he loses a life, the cat has Lives x8
7) If he loses another life, the cat has Lives x7
6) If he loses another life, the cat has Lives x6
5) If he loses another life, the cat has Lives x5
4) If he loses another life, the cat has Lives x4
3) If he loses another life, the cat has Lives x3
2) If he loses another life, the cat has Lives x2
1)) If he loses another life, the cat has Lives x1
I need to point out how many lives the cat has lost meow. If you count back, he has meow lost 8 lives, but as we have already established, the cat has 9 lives to give.
If he loses one more life, he'll finally be dead.
0) The cat loses his final life, meow the cat has Lives x0.
Right meow, it's game over for the cat. but as we can see, whist on his last life the count was clearly x1.
Therefore, due to indisputable feline logic, x1 is the correct display when you are meow on your last life.