Rule of three. Tried and tested.
Why does repetition need to be three times to stick in our minds? Does our brain register faster if it is in sets of three? Or is it able to decipher better when the information is available in sets of three? The rule of three is one of those things that are so ingrained in how we, as individuals, think that we don’t even notice the repetition. What makes “three” such a special total.
Neuroscience has an answer. Memory is created by the neural connections. More the neural connections better the memory. With repetition the neural connections are made stronger and hence it is one of the basics in learning (music compositions, dance steps or just plain academics). Basically, without repetition key synapses do not form. Hence it may be explained that it is not necessarily thrice but anything more than twice is repetition.
It may also be concluded that the rule of three is the brain’s way of codifying and organizing data to retain it. With more than three points, there is a risk that information will not be remembered. But there are always exceptions. There may be times two ideas seem sufficient or times when four ideas are absolutely essential. However, the more points one makes, the less likely they will be retained by the listener.
Another explanation is that the brain prefers simplifying tasks. Anything that is divided into three parts makes it easier for the brain to remember. A division of two would be two big chunks and a division of four would be too much for the brain to focus on and remember. But a division in to three parts helps the brain visualise it better. Example: Before, During, After OR Beginning, Middle and an End Or Past, Present and a Future.