Coming up with a brilliant idea is the purpose of a brainstorm. First appearing in 1930 in Harry Craddock's The Savoy Cocktail Book (the source of other drinks such as the Champs Élysées), the Brainstorm is the liquid realization of a brilliant cocktail idea. I discovered it in Difford's Guide.
Combine in a mixing glass with ice, stir as you contemplate something mind blowing, and strain into a chilled glass, preferably a coupe. Orange peel garnish optional.
Interestingly, Craddock specifically called for Irish whiskey in the Brainstorm, but other whiskey based cocktails in his book are silent about the whiskey's provenance. I'm certainly not complaining. I love Irish whiskey on its own, or in a drink such as a Tipperary or a Good Cork. The Benedictine DOM, a key part of cocktails such as the Honeymoon, adds a bit of sweetness to the equation, and the dry vermouth keeps the Brainstorm from being too sweet. Whiskey and dry vermouth make a nice combination in the Algonquin and my adaptation of the Brown Bomber, and it's the same here.
To quote a line from Madonna's song Vogue, strike a pose (imagine Rodin's The Thinker) as you sip the Brainstorm. So what's your brilliant idea?