From 1896 to 1900 Albert Einstein studied mathematics and physics at the Technical High School in Zurich, as he intended becoming a secondary school (Gymnasium) teacher. For some time afterwards he was a private tutor, and having meanwhile become naturalised, he obtained a post as engineer in the Swiss Patent Office in 1902 which position he occupied till 1909. The main ideas involved in the most important of Einstein's theories date back to this period. Amongst these may be mentioned: The Special Theory of Relativity.

—Biographical Note in Albert Einstein’s
Relativity: The Special and the General Theory,
Robert W. Lawson

It's terrific fun to read what the original thinkers had to say for themselves. I read parts of Relativity: The Special and General Theory by Albert Einstein, and found the letter about Einstein forgetting to eat lunch in Einstein: His Life and Universe by Walter Isaacson.

—A Black Hole Is NOT a Hole,
Carolyn Cinami DeCristofano

What connection can be made between these two passages?

DeCristofano was inspired by Einstein.
Einstein was inspired by DeCristofano.
Isaacson was inspired by DeCristofano.
Einstein was inspired by Isaacson.