Did you know that pi is a transcendental number? It transcends algebra. However, it is not the only transcendental number. τ (0.412454033640...) and e (2.71828182845904523536…) also transcend algebra.
So why don't we celebrate Mathematical Constant Day on 2/7? Or Golden Ratio Day on 1/6? How come pi is so lucky? Maybe it's the pie.