That feel when you realize that

Because we can do one action, we can do two actions... We have 1, 2, 3... ie N.
By adding opposite we obtain -1, -2... ie Z
By adding intermediate we obtain 1.1, 1.2... ie Q
By completing we obtain R
By adding two square roots of -1 we obtain i. ie C
etc...

All the mathematics are fixed because of the 1. Just that little seed and all the complexity of mathematics appear. That's just fucking impressive.