Jayapataka Swami: You see sometimes Lord Caitanya gives special mercy to the devotees. They may have a glimpse of a higher stage than they are on. So one may get a momentary ruchi, even at a lower stage. But when you reach the stage of ruchi, that means you are always getting the taste, always! If you get this taste, like a little taste then it goes away, that is the causeless(?) mercy. But if you continue then you will reach the stage where at least part of the devotional service, you get a taste.