one, or it could be a deep one, but it changes them. and it tells them there is something here. it's like a miner in a gold mind, and digging for so long and then finally he finds a little nugget of gold. maybe not the big giant gold nugget, but he finds enough of those there to give him the faith to keep working and moving on with the practice.
as they begin to do that what happens is that a small portion of the nature of mind is revealed. not the whole thing, but just something that is a clue that gives them the sense that this part of 