Here’s a belief I’ve held for a while but only recently been able to put into words: explanatory comments are often easier to understand than explanatory variable or function names. Consider a complicated expression with multiple sub-expressions. This expression is going to be difficult for the next person reading this code to decipher; we should make it easier for them. There are a couple of ways to solve this. We could break down the expression into sub-expressions, and assign those sub-expressions to intermediate variables. Or we could pull the expression out into its own dedicated function. In each case, the goal is to give either part or all of the expression a dedicated name. This name helps the next reader to understand the purpose or meaning of the expression.