Quoting Anne Morrow Lindbergh:

"If one sets aside time
for a business appointment, a trip to the hairdresser, a social engagement, or a shopping expedition, that time is accepted as inviolable.

But if one says:
"I cannot come because that is my hour to be alone, one is considered rude, egotistical or strange.

What a commentary on our civilization when being alone is considered suspect;
When one has to apologize for it, make excuses, hide the fact that one practices it.... like a secret vice."

Anne Morrow Lindbergh was the wife of the famous aviator Charles Lindbergh...who was the first person to
fly alone from N Y to Paris
In 1927. Flight time:
33 and 1/2 hours, without sleep.