It depends on the domain. I would be cautious about assuming that concise comments explaining what is being done in a block of non-trivial code are unnecessary. I have seen too many people write code they assume to be trivial (after spending days/weeks/months/years developing necessary background knowledge to understand it) when it's not the case at all. Debugging errors in undocumented code that involves several complex/opaque structures, nested function calls, and external libraries is not fun when you can't tell what step is at fault due to side effects, internal computations etc. not being clearly visible.