You could make up new numbers forever -- plus infinity

Last night after story time it was dark and quiet and I was laying between the girls, Winnie whispered, "Mom."
"Yeah?"
"What's the last number?"
"There isn't one."
She got this happy surprised look on her face and took a breath of wonder -- I said, "I know, pretty great, hey?"
"One million?"
"Not a million,billion, trillion, gillion, quadzillion or a bunch I don't even know. They just say infinity when they run out of numbers."