Euphoric dreams are very common among people who are generally happy, and have a great sense of well-being. Sometimes an endorphin release during sleep gives an almost erotic feeling.
Floating suggests your ability and desire to 'rise above' a situation, and your capability to handle most anything that comes your way.
This was probably a 'lucid' dream and the paralysis happens to keep you from flailing about ...or 'acting out' the dream..,possibly injuring yourself.