I dont think anything dreamt is doable. People dream of flying without wings or without any support or any means but actually it cant happen. Likewise there are many dreams which are hypothetical. But some dreams have physical existence.
Flying without wings or support dream depicts bad dream of witchcraft attack and such is not the kind of dream w are talking, however, with use of computers film makers make human beings look like flying which is fictional and cannot be real. I like your concept of dreams come true.
Sebastain, this can be linked to concepts of early gods, gods in general in fact, and semi-divine individuals and their gradual assumption of 'superpowers'-running exceptionally fast, flying, time-leaping. But surely these can be understood through envy of animals, and the creative imagination.
What exactly are you looking for? Some specific idea conceived by mind or any random thought or reflection of sub-conscious through dreams or some specific event or experience which may be mystic initially. Or you had some mystical experience which you want to test in physical world?