It’s all Greek to me is an expression meaning I don’t understand it. The Greek alphabet is unintelligible to anyone without learning.
As happy as Larry means extremely happy. Larry is a name as in the children’s radio series Toytown, where Larry the Lamb pronounced his name like a baa. However Graeme Donald gives the derivation from a dialect word, larry meaning confusion or excitement from larrikin – a corruption of larking (The Dictionary of Modern Phrase).
Jerry-building is substandard construction. There was a maritime phrase jury built describing emergency repairs to a ship. The reference book mentioned above gives a more thorough explanation of possible derivations.
Take the Mickey means tease cruelly.
A lazy Susan is a revolving food-stand on a table. (It saves work.) Whoever heard of anyone with the same name as me being lazy?
A lazy Betty is a pull-cord light switch, which may be operated from a bed. Betty is one of the shortened forms of Elizabeth. Bessie, Bess, Bet, Beth, Bethie, Liz and Lizzie are other diminutives. Eliza is a name in its own right.
Uncle Sam is a symbol of America inspired by Samuel Wilson.
John Bull is a typical Englishman.
John Brown features is a song –
John Brown’s body lies a-mouldering in the grave, but his soul goes marching on!
Punch and Judy are two glove puppets who appear in traditional puppet plays in striped booths usually at the seaside. A Punch and Judy Show includes Punch, who is violent, his wife, Judy, their baby and a dog. The puppeteer is hidden inside the booth.
Murphy’s law is that anything which can happen will happen. It is usually blamed when something goes wrong.
Name-dropping is mentioning the names of well-known people of one’s acquaintance in the hope of improving one’s own reputation.
Melchizidek is a name you may not have heard before. (The “ch” is pronounced “k”.) His story is to be found in Genesis 14:17-24
Hebrews 6:13-8:13 explains how Melchizidek foreshadowed Christ’s work as High Priest.