Stoicism

Everyone is born with a connection to magic. It's ingrained into their soul, why gods are alive and why we have artefacts people can use and how humans with no teachings can learn magic for example.

You, however, were born with your connection to magic severed. Perhaps you were born during a time of high magic, perhaps arcane magicks were weaved towards a 'Great Purpose/Work'. Whatever the reason, you are - for lack of a better term - 'Stoic in the Face of Magic'.

For you Magic has a harder time affecting you personally to the point that even legendary magical artefacts/relics will refuse to work for you after a certain amount of time.