down in the dumps	depressed
keep sb in the dark	keep sb unaware of sth
sth is not all it's cracked up to be	to be not as good as people say
catch sb's eye	catch sb's attention
right up one's street	within one's range of interest/knowledge
take things easy	relax
off the beaten track	isolated and quiet
come down to earth with a bump	stop dreaming and start thinking practically
in one's element	very happy/suited to situation
the crack of dawn	very early in the morning
get away from it all	wziąć przerwe od pracy, dać sobie trochę wolnego
run-of-the-mill	ordinary and not excited
as brown as a berry	very suntanned
over the moon	extremely pleased
get into the swing of sth	become accustomed to sth and start enjoying it
steer clear of sth	avoit sth
let one's hair down	relax and enjoy oneself
a new lease of life	a return of new energy and enthusiasm
one's best bet	most appropriate choice
round-the-clock	all day and all night