How do I explain bitcoin to someone who thanks money is still backed up with gold?

I was discussing bitcoin with one of my relatives, he still thinks we have the gold Standard which already was infuriating. Later, he asked "how can a digital currency have real life value. Money has value because its backed up by gold, sO tHaTs eAsY to uNdErstAnd"

Wtf Am i supposed to tell him??? I told him that he should learn to understand how money works and it doesnt makes sense to continue talking about bitcoin.

Edit: thinks, not thanks...