I wouldn't naturally think about summing lists in reverse so it becomes more cognitive effort to understand the code. I've seen plenty of termination condition

I wouldn't naturally think about summing lists in reverse so it becomes more cognitive effort to understand the code. I've seen plenty of termination condition bugs on reverse iterations that might back that up. A related thought is how modern code clean-up tools are doing things like reducing if-nesting e.g. turning this: if (open) { stuff(); close(); } into this, with early returns: if (!open) return; stuff(); close(); My feeling is that the first more naturally represents the idea I have of the behaviour and the second, like your reverse iteration, is an encoded version of that idea. I feel I have to make an extra cognitive step decode and reassemble it to create an idea of the behaviour. I suspect the further you stray from the natural idea, the harder the code is to read, validate by eye and the more likely errors are to crop in. I'm don't know how subjective this is. I generally don't have a strong feeling about early returns it's just I have been noticing the slightly greater cognitive effort they are causing me compared to the logical chunking that nested-ifs provide.