Idiom: to bury one’s head in the
sand; used as a verb

First Example:
Teacher: Joe, can we talk about your test?   
Joe: I know. I did terribly.  But I’ll do better next time.
Teacher: Isn’t this the third one you’ve
failed?         
Joe: Yeah, so?
Teacher: Well, maybe you should stop
burying your head in the sand and admit you need help.  If you fail another test, you won’t pass the class.
Joe:
Oh wow. Yeah, I guess I do need to do something.
Teacher: Why don’t you go down to the
tutoring center tomorrow? I hear they have some really great math tutors that
should be able to help you.

Meaning: The idiom «to bury
(one’s) head in the sand» is used when someone is ignoring a bad
situation. The idiom is based on the
idea that ostriches bury their heads in order to avoid danger; however, this is
actually a myth as ostriches do not hide in this way. Here is another example:

Tricia: I finally paid off my credit
card.   
Val: That’s awesome!  How did you do it?
Tricia: Well, for a long time I just buried my head in the sand about how
much debt I had, but one day I finally added it up and realized I had $20,000
in credit card debt.
Val: Wow! That’s a lot!
Tricia: Yeah. Once I finally admitted how bad it was, I
quit using my cards and paid off as much as a I could each month.  It took me a couple years, and it was really
tight, but I’m so glad I did it.
Val:
Congratulations

Meaning: In this example, Tricia uses the expression to explain the
she was ignoring the amount of credit card debt she had. 

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