Going into someone else's dream
Yes, it can be done. It's real. I have done so approx 36 times. It is not astral projection, although when in the astral, another persons dream can also be accessed. It is possible to change the dreamers thoughts, interact with the dreamer, and also join their dream. The dreamer can remember the interaction once awake. For me to do it, I need to go to sleep, become conscious or semi conscious when I am still asleep, think of the person, sense their energy, and I merge into their thoughts while they are asleep. The longest time I can do this feels like about 30 seconds.
The most significant 3 discoveries I have made is that (1) a persons dream can be partially reversed using thought control (literally using thought energy to reverse their thought processes), and they will not remember the change to their dream; (2) two (or more) people can share the same dream experience but not necessarily see each other in that same dream, but decribe the surroundings in the dream once they are awake, and (3) Fragmented thoughts in motion can be implanted to a person who can awake thinking they have generated those thoughts themselves.