OMG. The most comfortable saddle I have is my Brooks B17. Back when I first bought it I was talking with the lads at one of the bike stores "I've heard they can take some time to break in!" Can't remember how the rest of the conversation went but yeah.
Some people find them comfortable out of the box. I have a bony posterior and I did not. Holy jeebus! The break in process was painful! It was like sitting on a block of wood!
Talk about sit bone awareness!
Eventually and through suffering and determination I broke it in (or my posterior adapted!)