I have been clean a month and the cravings for drugs have pretty much subsided. But I wouldn't call it really a "craving" but on a daily basis I have the thought pop up "it'd sure feel nice to use right now" but it's generally pretty easy to shake the thought. I have been told though it'll probably be pretty much a lifetime of having thoughts or memories striking up randomly where you think of using. I have been told the occurrence of the thoughts slows down with time though.