According to The Independent, Hogan was born in Jamaica, Queens, and served as a member of the U.S. Army in Korea. Following an honorable discharge, he went on to study at New York University, before switching his career path from engineering to acting and later attending the American Academy of Dramatic Arts in Manhattan.

"After the first semester (at NYU), however, an astute professor suggested he take an aptitude test to determine if engineering was really the best fit for the gregarious young man," his family revealed in his obituary. "The test results produced two words: The arts. As Bob would say, 'That's when I gave acting a try'," the Hogan family added (via The New York Times). 

In Hogan's obituary, the actor's family also made a request that fans should make donations to the nonprofit organization DOROT in New York City or at the Alzheimer's Association, rather than sending flowers.