There is a lot of Dunning-Kruger in this thread.
If thinkandmull is having trouble with the concept that the cardinality (the “size”) of the set of all odd numbers is the same as that of the natural numbers, what will he make of the proof that the set of all rational numbers (i.e. all numbers that can be expressed as the fraction of two natural numbers: 1/2, 3/7, 235673/256777654 are all rational numbers) is countably infinite and therefore the cardinality of that set is the same as the set of natural numbers, in spite of the fact that there are infinitely many rational numbers in the interval between any two rational numbers (the rational numbers are said to be dense rather than discrete). The same is true for the set of algebraic numbers (i.e. all numbers which can be expressed as the root of a finite, non-zero polynomial in one varable with rational coefficients). Indeed the cardinality of the set of rational numbers is the same as the cardinality of the set of any natural number raised to the power of all natural numbers (e.g. {13459^1, 13459^2, 13459^3 …} = {13459, 181144681, 243802621579 …} and this true no matter how big the base is.
Whereas the cardinality of the set of real numbers can be proven to be greater than these and that proof is ingenious and satisfying.
I am always amused and bemused in equal measure by people who casually consider some mathematical or scientific concept and who, failing to understand it, blame their misunderstanding on some elementary mistake that they believe has been made by the best minds who for decades have considered, accepted and enlarged on the concept, rather than blaming their misunderstanding on their own ignorance of the subject.