When it comes down to it, our short term memories are rather feeble.
If I were to give you a number to remember without letting you write it down or record it like 2039383942 and later ask you for the number–it might be extremely difficult to accurately spout them back to me.
This is because your short term memory can only hold a limited amount of information in it and you likely didn’t have much time to commit the number to your long term memory either.
Now what happens if I tell you that this was a phone number? 203–938–3942…