I mean, I've written at most a couple dozen in my 7 years as a professional programmer (usually tight loops for perf), so sheer unfamiliarity is a big factor.

I mean, I've written at most a couple dozen in my 7 years as a professional programmer (usually tight loops for perf), so sheer unfamiliarity is a big factor. But yeah, syntax (what order the arguments go in) and off-by-one issues are the majority, I think. Plus figuring out what my initial accumulator needs to be. Idk, map/filter and friends are just a much more direct mapping of how I think of programming.