Ambitious humans and extraterrestrials seeking power over others would be heavily attracted by Earth's secret space programs.

At this time, in the solar system, there are at least 10 secret space programs.  Corey Goode and William Tompkins were two prime witnesses of these programs. William Cooper in the 1980s was probably the first whistleblower who blew the whistle on America's early involvement with aliens. 

The development of MKultra by CIA chief Alan Dulles laid the foundation of mind control in The Secret Space Program that Corey Goode was victimized by. The whole 20 years and back could be explained by the use of clones similar in the movie "US". Corey was a MILAB person (a military abduction child). He believed and still believes that he has "a higher and lower self". His higher self was transferred into a cloned body where he worked in the secret space program for supposedly 20 years. After unproven units of time, His higher self was sent back to his body in his bed where his lower self never moved. The integration between the higher self and the lower self, probably didn't succeed, but Corey woke up thinking that he'd learned many secrets of the universe.

Corey's stories also have elements of the movies "Total Recall " and "John Carter on Mars". Check them out. These are the best explanations, I can come up with on this extraterrestrial technology of 20 and back. 

Karla Turner received witness testimony from abductees about similar phenomena and the use of illusions and lies to confuse and control victims.

Check this out. The greatest alien mind control movie of all time is"They Live". This is a modern version about the implants that "The Annunaki" used to make mankind into docile slaves.   

Another researcher looked at alien abduction of the human soul as a desire for some different kind of "battery".

From my own past life memories and research, I concluded that human DNA and memories were valuable commodities for energy and entertainment purposes of degraded extraterrestrials. 

One could look at the secret space programs as a way that Lucifer shares his power with unsuspecting humans and ETs.  

Satan tempted Christ with power over others on Earth. Jesus answered back "What does it profit a man to gain the whole world and lose his own soul?" 

Enjoying singing along with this hymn: "I shall not be moved".