Many things people do even today on a universal scale are based on superstitious beliefs.
For example
the birthday observance has its origins in astrology. You will recall that astrology attaches great importance to one’ exact birth date as the position of the planets and constellations is said to influence one’s life. In an earlier article It has been proved that the positions of them now have shifted substantially from that of the time when the charts were made. Altogether different planets and constellation are in place now and it is ridiculous to consult those outdated and obsolete charts made centuries before.
The birthday cake seem to be related to the Greek Goddess Artemis, the birth of which was celebrated with moon-shaped honey cakes decorated with candles.
The black funeral dress was originally worn as a ploy to escape the evil spirits which were hovering during a such an occasion. In some of the Black African nations people paint themselves white! There black being the accepted shade white will keep away the spirits!