From my perspective at the time, I would guess that for humanity as a race to fully accept that all of existence originates from a single source, and that time and space are not what they seem (traveling, for example, to the moon, or even better, to "distant" planets), it is still a ways off. And, it will seem to be a revelation as some kind of advanced idea. Similarly to gaining the perspective enough to learn and accept that the Earth is round.
However, it seems to me that for humanity to accept these things is just a little tiny starting point, it's like humanity just being born ... or at best, having a little first step as a baby. Little, baby humanity. I love you little baby humanity.
*holds little baby humanity in arms*
*sings to little baby humanity*
*looks into little baby humanity's wide eyes*
*wonders what little baby humanity will grow up to be*
I also think though that there are people of all sorts who do accept this already.