Please stop talking about your imaginary girlfriend, it's embarrassing honestly.

It's Infinity! Infinity -1? also infinity! Well what about infinity times infinity? Believe it or not, infinity! ♾️

You could use ℂ

Just like birds, complex numbers aren't real!

Screw you sqrt(-1), you aren't even a real number, you poser!

What you're probably thinking of is Ordinal numbers.

As for your second question, I don't think any "last number" could exist unless we explicitly declared one. And even then... I'm not sure what utility there would be in declaring a "last number".

Which of the infinities? There are many, many :D

The smallest infinity is the size of the natural numbers. That infinty, Aleph zero, is smaller than the infinity of the real numbers, Aleph one. "etc."

See https://en.m.wikipedia.org/wiki/Cardinal_number

There is nothing "past" infinity, infinity is more a concept than a number, there are however many different kinds of infinity. And for the record, infinity + 1 = infinity, those are completely equal. Infinity + infinity = infinity x 2 = still the same kind of infinity. Infinity times infinity is debatably a different kind of infinity but there are fairly simple ways of showing it can be counted the same.

Essentially the number of numbers between 1 and 2 is the same as the number of numbers between 0 and infinity. They are still infinite.

i isn't a real number, you imagined it

not a real number

Russell is that you? Please stop breaking my formal systems

[0-9]*\.?[0-9]*

edit: ok no empty strings [0-9]+\.?[0-9]*

Oh, so complex numbers are not numbers now?!