A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

have something under one’s hat • keep something
under one’s hat
have something under one’s hat—(coll.) have knowledge of
smth.: He had something under his hat; a tip-off straight from
headquarters, news of high international importance.
keep something under one’s hat—(coll.) keep smth. a secret;
keep smth. to oneself: “Nothing about that in the papers, is
there?” “Not yet. Keep it under your hat.”
See also: pick something out of a hat / pull something out of a
hat.
have the advantage of something • have the advan-
tage over something
have the advantage of something —possess smth. that is useful
or is likely to bring success: Galsworthy’s plays have the advan-
tage of acting well — unlike much literary drama.
have the advantage over something —be better, stronger, etc.
than another item of the same kind: The new system of air
cleaning has many advantages over the old one.
have the baby blues • have the blues
have the baby blues —(coll.) feel sad or depressed when preg-
nant: After seven months, Karly had the baby blues. She was
feeling sad.
have the blues —(coll.) feel sad or depressed: Doctors told
her she just had the blues, and although they offered her med-
ications, they did not keep her in the hospital.
Note: 
The expression does not correlate in meaning with the
phrase have a blue—(Austral. sl.) get into an argument; start a
fight or brawl: There is an old bloke who sits on the verandah
of the pub who won’t drink inside because he had a blue with
the publican.
have the best of it • make the best of it
have the best of it—
1
. have the advantage: Though the inside
passengers had had the best of it during the night, the outside
passengers had the best of it now. 2. be the winner: In terms
of overall championship wins, the Dutch had the best of it as
they took three of the four titles on offer.
make the best of it—accept an unfavorable situation and try
to obtain the best possible results from it: It was anything but
the perfect trip, but we made the best of it thanks to Joe.
See also: do one’s worst / make the worst of it.