Spawning from here:
We usually don't care whether indices start at $0$ or $1$ (except in the sense we'd rather start with our favourite if it doesn't matter, and the old joke is that set theorists start at $0$ and non-Peano number theorists start at $1$). I say usually, because there are a few cases where we do:
- If there's programming involved, use the same indexing for your mathematical exposition as in the code itself, which varies by language. For example, Python starts at $0$, whereas R starts at $1$.
Why did they choose to start from $1$?