I don’t know how you could possibly reason about options without understanding delta, and gamma makes sense to me too since it’s just the derivative of delta as the underlying value changes.
Just like pi means different things in different contexts. It might be a permutation, projection, a function which counts prime numbers, or it might be half the period of sin. I might write π(10) = 4, or π ≈ 3.14…, or for π in P, etc. I might say that π is the right inverse of ι, in other words π∘ι = id, and point to some digram with a bunch of arrows.
Delta is not just “a change” in this context. It is specifically the rate of change of an option’s value with respect to the value of the underlying security. Just like pi, delta and gamma mean different things in different contexts.