Subject that fascinates egotist? (5)
I believe the answer is:
theme
'subject' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for theme that I've seen before include "Topical item" , "Thread, melody" , "Main idea or topic" , "A subject or repeated melody" , "Subject; recurring idea" .)