That’s a common myth; what it actually does is water it up. There’s still 2 or 3 ounces of 80 proof booze in the glass, but now it has a few more drops of water in it.

At one point in Casino Royale, Bond says he likes his drinks “very cold” which is probably the realistic reason for shaking. You can get a drink a lot colder a lot faster by shaking than by stirring.

There’s also…Ian Fleming wrote Bond to have a lot of cool and sophisticated opinions like that, at the time it sounded cool to have a custom bar order, whatever it was. Nowadays if you walk into a bar and start issuing a list of instructions to the bartender you look like a prick. If you’re in an actual bespoke cocktail bar they probably have a style they’re going for, or sir, this is an Applebee’s.