bury one’s head in the sand.逃避現實
——I lost my job, and I feel blue these days
——Hey，Don't bury your head in the sand. Everyone’s life is filled with ups and downs，pull yourself together.
——我丟了工作，這些天心情很不好。
——Hey，不要逃避現實了。每個人的生命中充滿了起起落落，振作起來吧！

come down to earth / come back to earth回到現實，不再幻想
You have a fit of enthusiasm, Tom, but you must come down to earth. We can't possibly afford any of your suggestions.
湯姆，你滿懷熱情，但請回到現實中來吧。我們或許不能接受你的任何建議。

face the music勇敢地面對困難；接受應得的
I didn’t finish my work, so I have to face the music.
我沒做完功課，所以我只得硬著頭皮挨訓了。