This euphemistic version of Einstein's 1918 idiocy is easy to explain:

David Morin, Introduction to Classical Mechanics, Chapter 11, p. 14: "Twin A stays on the earth, while twin B flies quickly to a distant star and back.. [...] For the entire outward and return parts of the trip, B does observe A's clock running slow, but ENOUGH STRANGENESS occurs during the turning-around period to make A end up older." http://www.people.fas.harvard.edu/~djmorin/chap11.pdf

Special relativity predicts that either twin sees his brother aging more slowly, and the looming reductio ad absurdum can only be stopped by enough strangeness. Simple. The brainwashed world would never ask for more explanation.

What is totally mysterious and inexplicable is Einstein's HOMOGENEOUS GRAVITATIONAL FIELD - where Einstein found the courage to introduce the incomparable idiocy and why nobody has questioned it for more than a century:

Albert Einstein 1918: "A homogeneous gravitational field appears, that is directed towards the positive x-axis." http://sciliterature.50webs.com/Dialog.htm

https://pbs.twimg.com/media/DafYwspX0AAixYo.jpg

Pentcho Valev