Understanding the entirety of a long function often takes quite a bit of time. Sometimes you just want to know what a section of code does, not how it does it.

Understanding the entirety of a long function often takes quite a bit of time. Sometimes you just want to know what a section of code does, not how it does it. If I'm touching big() and doFirstBit() for a code change, it'll be a hell of a lot faster if I don't have to read through doSecondBit(), doThirdBit() etc.