You don't have to fly especially high to become detached from humanity. Try climbing a tall building and looking down. A couple floors up, the once easily discernable facial features of your fellow humans will begin to blur. Their faces might turn into indiscriminate blobs. Climb the equivalent of another storey or two and you will no longer be able to hear their voices. From a very tall building, you might not pick out individual cars. The hum of the city might start to drift away.
When taking off in an airliner, the process is speeded up. Within seconds, the world will have fallen away to such a degree that you might have a job to identify even major landmarks and cityscapes. It will seem like you have entered another world - even though you know it is the same place.
From his capsule, Michael Collins would have been able to watch the lunar module descend to the surface of the moon. But Neil Armstrong and Buzz Aldrin might just as easily have been a whole galaxy away. Similarly, the shimmering blue planet Earth must have borne scant relevance to the voices on the radio from Houston.
And the same must go for time. A distance of a few years might not make a whole load of difference to your worldview, but look back over a decade and see what happens. Consider a lifetime before your own and you're suddenly staring into an abyss - a great unknown, full of mystery and educated guesswork.
It would be wonderful to see through time. And, just as telescopes and microscopes allow us a peek into different spatial dimensions, maybe one day we will be able to do just that. In the meantime, all we can do is follow the vague treasure map that history has left us.