Answer: At these conventions, we need to reach the entrance to the upper world, to begin to feel it, at least temporarily!
Before a person enters the upper world, he moves like a worm that tries to get out of a radish. He sticks his head out a little bit and pulls back, comes out and back again. He moves like a piston, back and forth.
Similarly, we do the same: We stick our heads out and back, stick out and back, until we accumulate the desired pressure and use it to finally come out of that radish, from our world. Thus, there are moments when we gnaw at the peel of that radish and begin to break it.