The ability to produce an infinite series of numbers (by adding another one) does not constitute a proof of existence of anything infinite outside one's mind.
Good philosophers, like Leibniz and the Indian tradition, which includes early Buddhists, have postulated this, but popular memes are much stronger.
The ability to notice some inherent patterns of natural phenomena, such as the ratio of a circle's circumference to its diameter, does yield this ratio to be immortal, or any other inferred constant.
Math does not exist outside people's minds (contrary to the popular discourse from the Zen And Art Of Motorcycle Maintenance). Only a few of what we call conservative forces and different forms of what we call energy (or matter if you like) which are different aspects of the same That, to which human categories are inapplicable.