I live in one of the last places in the States where Ascension is still celebrated today, on the 40th day after Easter. In most places it has been moved to the weekend and has replaced what used to be the 7th sunday of Easter.
Ascension always brings up some cloudy memories for me. It was, I think, at a vigil Mass for this day that I first presented myself to a parish for the catechumenate. That was 14 years ago, though it seems longer.
In the days approaching Ascension we always hear Jesus' farewell discourse from the Gospel of John. Never mind that the Ascension itself is only in Luke-Acts; that's a funny business for the Scripture scholars to figure out.
The whole thing reminds me of a brother here who famously said about the life of prayer, "God goes away." And that's the bizarre thing about prayer and devotion; the more we are drawn to God the less we feel as if we can say what we are even talking about when we make an utterance like "God."
Spiritual writers get at this particular anguish in different ways. Gregory of Nyssa talks about how prayer is both movement and rest at the same time. The author of the The Cloud of Unknowing tries to convince us that our loss of clarity and knowledge is itself an indicator of progress. John of the Cross talks about the "rays of darkness" which obscure the mind and force us to let go of everything we previously thought of as our "spirituality."