Egon Spengler is not so much ashamed as "strongly" considers irrelevant, mainly because he sees science as relevant. Spengler's faith in science was also tested in one episode where the Ghostbusters get abducted to the ghost world by the ghost of Al Capone. Spengler's scientific equipment fails until he is told by former capos of Capone (who aid the Ghostbusters in revenge for Capone double-crossing them) that only magic can harm ghosts in the ghost world as opposed to science harming ghosts in the human world, thus forcing Spengler to accept the wizardry methods of his ancestors to defeat Capone. He is
Egon Spengler intellect switched with Slimer's. He has however, ceased his sugar junkie ways, only to briefly be tempted by a candy store when in Slimer's body (a likely fact that Slimer was an overt glutton). It is revealed in "The Boogieman Cometh" that, as a child, Spengler was stalked by the boogieman, a supernatural monster that fed on the fear of children and hid in their closets, and was particularly fond of Spengler's fear; it was these encounters with the creature that inspired Spengler to study the paranormal, and as an adult, he would battle the Boogieman twice and defeat him.