A big fish in a little pond.

But the Americans are oblivious.

He laughed off others' talk, the outlook of which was like that of a frog in well, and did not bother to argue with them.

We are all in the gutter, but some of us are looking at the stars.

Many students have tunnel vision when it comes to choosing their major - they pick their major on the assumption it's the only fast track to their lucrative dream job.