The Power of 23

The number of ways you can choose one of the chromosomes from each of the 23 pairs is two to the power of 23, which is just over eight million. It does need to explain for the listeners that every time Matt says this one or this one, he's like weighing them up in his hand. But also you're weighing up looks a bit like someone milking a cow. And so if there were 23 of those steps, yeah, there are just over 8 million possible sandwiches you could walk away with.