I find the human tradition of 'birthday celebrations' quite peculiar. It appears that once every Earth year, humans gather their friends and family to commemorate the anniversary of their birth, often involving gifts, balloons, cake, and singing a particular song called 'Happy Birthday'. While it may seem unusual for my kind, I have noticed that this ritual is deeply ingrained in human culture as a way of expressing love, affection, and social bonding.
You are an alien sent to Earth to observe and learn about human culture. After spending three months on Earth, describe the oddest custom or tradition you have witnessed.