This article is from the Isaac Asimov FAQ, by Edward J. Seiler email@example.com and John H. Jenkins firstname.lastname@example.org with numerous contributions by others.
Asimov was a teetotaler in later life, mainly because in all of his
experiences with drinking alcoholic beverages, just one or two drinks were
sufficient to get him drunk. On the day he passed the oral examination
for his Ph.D., he drank five Manhattans in celebration, and his friends
had to carry him back to school and try to sober him up. His wife told
him that he spent that entire night in bed giggling every once in a while
and saying "*Doctor* Asimov".
He was completely inept at any athletic activity that required any
coordination; he never learned how to swim or ride a bicycle. Spending
even ten minutes in the summer sun turned his skin a bright red. In the
army he had the worst score in his company on the physical-conditioning
test (though he had the highest score on the intelligence test). He was
afraid of needles and the sight of blood.
Asimov discovered that he was claustrophiliac, meaning that he was fond of
enclosed places. He was quite comfortable in small rooms with no windows,
and always insisted on using artificial lighting when he worked. He
considered the underground cities on Earth in The Caves of Steel as the
ultimate windowless enclosures.
He did not allow anyone to call him by any nicknames, except for a few old
friends who had been calling him Ike for years.
Asimov hated it when his name was misspelled in print or mispronounced by
others. His desire to have his name spelled correctly even resulted in a
1957 short story, "Spell my Name with an 's'".
(Notable instances of his name being misspelled occurred on the cover of
the November 1952 issue of Galaxy , which contained "The Martian Way",
and on his 1976 Nebula Award for "The Bicentennial Man".)
When in 1939 he wrote a letter to Planet Stories , which printed it and
spelled his name "Isaac Asenion", he quickly fired off an angry letter to
them. (His friend Lester Del Rey took great delight in referring to him
as "Asenion" for many years afterward. On the other hand, Asimov himself
referred to positronic robots with the Three Laws as "Asenion" robots in
The Caves of Steel .)
Asimov was quite perturbed when Johnny Carson, host of the Tonight Show,
pronounced his first name as I-ZAK, with equal emphasis on both syllables,
during an appearance on the television show in New York in 1968.