There are many things in life that we are unable to understand; they go beyond the mind, and thus beyond understanding. A typical example at this magical time of the year is how Christmas presents can be delivered simultaneously on the 25th of December by you know who... The truth is that science surprises all of us again, with Quantum Physics providing all the answers children need.
I love the linked article, and how it can be extended to other areas we don’t understand, whether as a child or an adult!
The key lies in the fact of observation. Provided that nobody seeks to measure the effect with more than a certain amount of precision, the particle keeps all its options open. But if someone looks too closely, the particle makes its choice. In the language of physics, its quantum wavefunction collapses. Now, let's think of Father Christmas as a particle, obeying the rules of the quantum world. Following the logic of the two-slit experiment, it is perfectly possible for him to visit all the good children of the world simultaneously, provided that he does so unseen.