to be very close friends
sehr enge freunde sein (zehr enge freund zein)
"Those two have been thick as thieves since childhood."
"Diese beiden sind seit ihrer Kindheit sehr enge Freunde." (Dize beidn sind zait irer kindhait zehr enge freund.)
to be lost in thought or imagination
to create the base or starting point for something
to start working seriously
not paying attention; lost in thought
when something begins to decline in quality or popularity
to fail to experience something enjoyable