Well, could you? A determinist who believes that the world unfolds in an inexorably preordained manner would say not. If, on the other hand, you believe in free will, you might feel sure that other decisions were available to you, other paths not taken. “I could have done otherwise” is sometimes taken as the very definition of free will.

But asking if you could have chosen differently is not a yes or no question – in fact, it is simply devoid of meaning. If free will exists, it’s not to be found by asking whether we could have chosen differently.

Sure, that sounds odd. But if we want to talk about actual physical reality, such hypotheticals are irrelevant. Think about it. If you’re wondering whether you should have bought that other car, what does that really mean? You pondered it for days, all of that cogitation feeding into your decision. A whole bunch of other stuff, working out of conscious sight, was influencing your choice too – even, perhaps, what you had for breakfast. (A study in 2011 found that judicial rulings are systematically more lenient after the judges’ lunch break.) What exactly do you imagine changing, then, in this world where you chose differently? Where do you stop? There is no such world in which “everything is the same except my decision”. The decision is not somehow superimposed on the rest of the world, but emerges from it.