Conversation so far:
What sport did Jimmy Greaves play?
Soccer
What was the last team Jimmy Greaves played for?
Woodford Town Football Club
Did Jimmy Greaves like attending West Ham?
Greaves was struggling with his fitness. He felt he had become a journeyman footballer and lost motivation as he believed that few of his teammates could play good football.
What year did Jimmy Greaves quit the Bees?
He chose to leave the Bees early in the 1978–79 season
Did Jimmy Greaves learn a lesson at West Ham United?
Greaves later admitted his regret in making the move to Upton Park.
Did Jimmy Greaves like attending West Ham United?
Greaves was struggling with his fitness. He felt he had become a journeyman footballer and lost motivation as he believed that few of his teammates could play good football.

Question: Why did he leave West Ham at first?
Self-contained rewrite: Why did Jimmy Greaves leave West Ham at first?