They did all not have the same dreams. One saw an angel float down from the sky and roll his stone, one saw an empty tomb, one saw him in disguise while walking and then broke bread and ate fish with him, in another dream he popped in and out of a locked room, and then Tomas finally saw him in a dream and poked his wounds. Even the account of the ascension was an account of what was seen and heard in a dream.
Ascending bodily into heaven is not about bodily floating up into the sky.
What does the DM-5 Psychology Manual say about people who can't tell the difference between actual reality and what is only possible in the dream world?