it was from the wiki.
"After ~4 weeks age, the smell of ammonia will become apparent while the creamy golden interior will become ever-more liquid. This is the preferred age of B/C snobs. But eventually, even the hardiest of B/C-lovers will concede defeat to an odor that is “not far removed from wet gym kit that has been allowed to fester undisturbed inside a plastic bag for more than a week”. If the cheese reaches this stage, it should be thrown out, or buried."
Personally the smell of ammonia is not desired.