Since you are dedicated to your spiritual growth and you dealt with the same ascension symptoms a few months or years ago, sometimes more than once already, why do they come back?
Because we learn in a spiral. We think from learning facts at school that learning is linear but learning most often happens in a spiral.
We go through various issues in our life, one at a time, in a circular fashion and when we have completed the circle, instead of the circle being perfect and our being completely at peace and enlightened, we/the Universe cranks it up a notch and we go over the same circle again but at a higher vibration. Some say at a deeper level. I like to think that I am getting closer and closer to the Divine so I think of it as an upward spiral.
We re-visit the same issues, from a more enlightened or a lighter or wiser perspective and we refine the art of being once more. It keeps on happening and eventually we accept it and stop acting surprised when it does! :o)