a big fish in a small pond

“a big fish in a small pond”
to have a lot of influence only over a small area; people who are important but only within their limited circle of influence
مهم بودن در یک فضای محدود
Example 1: Steve has both a Ph.D. and an M.D., yet he’s content with his practice at a rural hospital; he prefers to be a big fish in a little pond
Example 2: He thought he was important, but Harry was just a big fish in a very small pond