Einstein said in a basic way, before getting into the physics of it, what relativity is. (But where on this green earth did I read it!?)
The example he gave to make sense of it all for poets and other lay people involved a ball thrown from a train over a canyon where two observers witness the purple ball soar.
What he said was that the two observers of the ball as it is thrown from the moving train will see and then give witness of seemingly two different events.
One will see the ball fly past his/her train window horizontally without appearing to lose much height, and s/he will not see the ball descend or land.
The observer in the canyon will see the ball descend and s/he will see the ball land in the canyon.
Time is viewed similarly.
I think Richard Feinman and any of a host of smarties would say that I can’t rightly use “Everything is relative” because it only applies to science; even though all people with their varying life experiences and their literal dis-similar positions in space/time never experience or perceive the same world in the same way. Coo coo ca choo
All I know is I must be on different planet than mostpeople.