Complex sentence: He used the phrase "a piece of cinema beefcake" to describe himself as an actor during that period, and felt it was after his return home from military service that he learned to act properly and began to mature as a performer.
Split into simpler sentences: He used the phrase "a piece of cinema beefcake" to describe himself as an actor during that period. He felt that after his return home from military service, he learned to act properly and began to mature as a performer.