USA, 1942—over-ready to shoot at anything at any time or on slight provocation—during and following WWII, ‘happy’ was used as the second element in compound adjectives relating to mental instability associated with the first element
The noun ‘armchair’ is used as an attributive modifier meaning: 1) based or taking place in the home as opposed to the world or environment outside; hence, chiefly depreciatively: 2) lacking or not involving practical or direct experience of a particular subject or activity.
be totally focused on your objective—USA — already well established in 1932—originated in the image of God’s watchful eye upon the sparrow, with reference to the gospel of Matthew, 10:29-32
USA, 1883—exclamation of surprise at seeing something or somebody unexpected—alludes to a hunter who will lament seeing all sorts of game when he goes out into the woods and fields without his gun
alludes to a British cavalry charge in 1854 during the Battle of Balaclava in the Crimean War—the phrase has had a variety of meanings, depending on the acceptation in which ‘charge’ has been used
with allusion to food served up on a slice of toast—1877 ‘to have someone on toast’: to have someone at one’s mercy—1886 ‘to be had on toast’: to be cheated