I'm prone to addiction and have kicked both alcohol and cigarettes. I still get *seemingly random* cravings for both from time to time. It sounds like there's a strong association with hypomania and dipping, so it's probably not totally random - your body has probably learned that hypomania means it's time to dip, so the cravings kick in stronger. That was the hardest part for me quitting my vices, breaking the associations in my every day life that triggered an urge to use.