A common caricature of the view of the mediaeval scholastics is that they wondered whether the number of angels who can dance on the head of a pin is infinite or not. In fact, this calumny was invented much later.
But another common view is that, after Aristotle told people that it was forbidden to think about completed infinities, nobody did so until Cantor broke the barrier.
I don’t think there was ever a time when people didn’t think about infinity. So I was interested to discover the metaphysical poet John Donne, in his poem Love’s Growth, perplexed by the question whether it is possible to make an infinite set bigger by adding something to it:
Methinks I lied all winter, when I swore
My love was infinite, if spring make it more.