10 months later bill revisits his spaghetti code. forgets absolutely everything and refuses to elaborate. this wouldn't have happened if Bill forgot to comment on his code

Basic rule if someone claims X magically solves a problem they don't follow X and are a huge generator of the problem.

For example people who claim they don't need to write comments because they write self documenting code are the people that use variable names x1,x2,y, etc..

Similarly anyone you meet claiming Test Driven Development means they have better tests will write code with appalling code coverage and epically bad tests.