Why do i keep having dreams about doing Ecstacy?

so , I used to be hooked on extacy for about 4-5 months about 1 year ago from now, Used to do pills every day probably done over 250 - 300 pills, So , ive been clean for about 2 months now, last time i used was at a concert on december 30th and before that i was doing it once a month, Why do i keep having dreams about using, Always about me taking a bunch of pills and being high my whole dream, Is this a sign? Craving? Why is this? !