I think what David Mermin thinks:
"That no inherent meaning can be assigned to the simultaneity of distant events is the single most important lesson to be learned from relativity."
Also: at any point in spacetime (e.g., at and event), any other event that is outside the light cone could be in the past, present, or future depending on how you move, locally.
Since this is feature of special relativity is called the Andromeda Paradox (https://en.wikipedia.org/wiki/Rietdijk–Putnam_argument), and Andromeda is very neatly 2.5 million light years away and approaching us at $v=c/1000$, it is very easy to calculate that right now, on a planet in Andromeda Galaxy, it is:
$$ 2020{\rm AD} + 0.001\,{\rm ly/yr}(2.5\times 10^6\,{\rm ly}) = 4520{\rm AD} $$
right here on Earth, now, ...., over there. Frankly, that disturbs me more than a squiggly line on a Minkowski diagram...though they are equivalent.