He may be referring to the on boarding process + first commit. Generally you'll have a few classes that introduce you to Google's build tools and any technologies that are relevant to you/your team. Then you'll start work and go through your first code review. This is probably what is refereed to as 'initiation rites'. Depending on the size of the change you may get a handful of comments or quite a few. After going through the code review process you will have successfully internalized Google's commitment to code quality. Generally you'll get a bunch of comments and suggestions that seem nitpicky but help keep things consistent and a few that are eye opening and help you become a better engineer.

I'm guessing he means readability. Google fetisihizes consistency, even at the cost of ingenuity and productivity. Heroism is a virtue at some other companies; at Google, it's a sin.