Why is Santa Claus not true?

Technically he does. He's just dead.

"Santa" is a nickname for a real man known as Saint Nicolas, who was a Bishop from the 4th Century.

Saint Nicolas largely devoted his life to children and orphans, bringing them gifts and food on Christmas Day.

So, Santa, or Saint Nicolas as his real name is, actually does exist, but he's been dead for thousands of years. He is the founding father of gift-giving at Christmas time.

The red outfit that Santa wears however is fictional. Saint Nicolas wore the standard Bishop uniform through his life (which was green). The red outfit was actually invented by Coca-Cola in one of their Christmas adverts, because the colour of Coca-cola is red and green represented one of their rival companies which produced lemonade.

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