Fortunately!

Brace yourself, you're in for some math!

There are three theorems you cannot escape if you were a math major. Those are the three fundamental theorems; the fundamental theorem of arithmetic, the fundamental theorem of algebra, and the fundamental theorems of calculus.

For public consumption i will take some liberty and smooth out the mathematical complexity. :-P. So in very simple terms, the first implies that every composite integer (>1) can be factored into primes uniquely (e.g. 12=2^2*3^1) where the second merely states that a polynomial of nth degree with complex coefficients has exactly n complex roots e.g., the cubic p(x) = x^3+8 has three roots -2, 1+sqrt(-3), 1-sqrt(-3). The third i will spare you, but it suffices to say the twin theorems make explicit the inverse nature of the connection between the concepts of differentiation and integration. So, if you derived the constant function 1 from the function x, then you need to integrate 1 to get back to x, will be an example, crudely presented.

Hidden within each theorem are some cautionary details. The first lets you switch the order of the said unique factorisation, the second lets you accept multiplicity of a root to fulfill the count of n, while the third admits that the crucial inverse link is, um, one injection short of an isomorphism.

No matter how fundamental the premise of a structure appears, it is no more fundamental than the axioms it is built on. Axioms proposed and accepted by human beings. Sans preuve.

Sometimes life's like math. Much as you like to deny it. We see it all the time. Human beings adhering to structures pre-defined for them by someone else long long time back. Simply because it makes them feel defined and thereby, safe.

Then again, not all of us are in need of a definition. Some of us just know better.