How about 'Smart alec.'

Oxford Advanced Learnners Dictionay defines it:

(also AmE. smarty pants / smartt-ass, BrE. smart-arse). noun (informal, disapproving) somebody who thinks they are very clever, and likes to show people this in an annoying way.

By the way, I had tried to be an “instant omniscient” when I worked as an account executive in ad agency to show off I know everything that the client wants to know, though I did know little or nothing about their business, and had no solution to their problems. I was an ignorant (or stupid) omniscient at that time.

How about 'Smart alec.'

Oxford Advanced Learnners Dictionay defines it:

(also AmE. smarty pants / smartt-ass, BrE. smart-arse). noun (informal, disapproving) somebody who thinks they are very clever, and likes to show people this in an annoying way.

By the way, I had tried to be an “instant omniscient” when I worked as an account executive in ad agency to show off I know everything that the client wants to know, though I did know little or nothing about their business, and had no solution to their problems. I was an ignorant knowledgeable and false specialist at that time.

How about 'Smart alec.'

Oxford Advanced Learnners Dictionay defines it:

(also AmE. smarty pants / smartt-ass, BrE. smart-arse). noun (informal, disapproving) somebody who thinks they are very clever, and likes to show people this in an annoying way.

How about 'Smart alec.'

Oxford Advanced Learnners Dictionay defines it:

(also AmE. smarty pants / smartt-ass, BrE. smart-arse). noun (informal, disapproving) somebody who thinks they are very clever, and likes to show people this in an annoying way.

By the way, I had tried to be an “instant omniscient” when I worked as an account executive in ad agency to show off I know everything that the client wants to know, though I did know little or nothing about their business, and had no solution to their problems. I was an ignorant (or stupid) omniscient at that time.