Birthday, as its name implies, refers to the day when a person is born and the day when he turns one year old every year. But folklore in some places believes that this is also the "Good Friday" of mothers. Because the technology in the past did not change with each passing day like today, when a mother gave birth to a child, there was a saying that "one foot was in the coffin and the other foot was outside the coffin". So they think that on that day, they should give priority to filial piety to their mothers.
The custom of lighting candles on cakes originated from the Greeks. The Greeks lit small candles on a full-moon honey cake and put them on the altar of the temple in themis to worship the moon god. According to traditional folk beliefs, candles lit on birthdays have magical power and can realize wishes. Since humans began to set up altars to worship the gods, lighting small candles or making a fire has a mysterious and special significance.