If you write a piece of code and it seems simple to you, but other people think it is complex, then it is complex.
- John Ousterhout, A Philosophy of Software Design
When you’ve finished writing a module or bit of functionality, you have likely just finished building for yourself some mental chunks and loaded up a lot of context on the changes involved (Everything is chunking). Your colleagues, who are going to have to both review and likely later modify your new code, are in a substantially better position to tell if your change is overly complex.