Yes, you should understand what a function does when you call it. Not everyone who looks at a codebase is modifying the codebase or adding new function calls.

Yes, you should understand what a function does when you call it. Not everyone who looks at a codebase is modifying the codebase or adding new function calls. The person referencing the code may already be 1-level deep in parsing the implementation. Not all abstractions will seem like a magic incantations when you use them. Something like "convertToCamelCase" conveys its purpose clearly enough that the reader can assume what the low-level operations are. They don't need to look at these operations every time they need to reference the code.