But if Mr. O'Brien was soaring, Mr. Letterman was roaring Wednesday night, unleashing a torrent of biting commentary about NBC, and digging into his apparent lingering bitterness about how it threw him over for Mr. Leno in the early 1990s.
He has made apparent his bitterness over his rejection by Al Gore, his 2000 running mate who endorsed Howard Dean, saying pointedly that he was unwilling to discuss his "sense of loyalty".
Many of the official tributes to Nelson Mandela, such as the one from David Cameron, have emphasised his ability to forgive, and his apparent rejection of bitterness is part of what made him extraordinary.
But despite his apparent show of bitterness, he still appears to be a fan of the Inglorious Basterds actor, sporting a T-shirt with a picture of a youthful, sun-kissed, open-shirted Pitt while carrying out his work.
In the interview, the account of which begins of the front page of Le Figaro, Mr. Dumas' bitterness is apparent.
And flavor chemists have found that high alcohol levels accentuate a wine's bitterness, reduce its apparent acidity and diminish the release of most aroma molecules.
On any sign where they mention the opposing view, their anger and bitterness is so apparent that it totally undermines anything they're saying.
What was originally a color designation eventually came to be a formal American style characterized by forthright flavors of malt and the readily apparent presence of American hops, which convey bitterness along with piney, grapefruit aromas and flavors.
A number were also driven into extremism, bitterness and paranoia by the apparent failure of even the largest demonstrations to change the policies of the Johnson and Nixon administrations.
