At this time of year, people are getting involved in traditions.
We've already had Thanksgiving in America. Now Christmas, Hannukah, and New Years Day are approaching.
No matter when or where humans have lived, it seems like every culture has had traditional celebrations at certain times of the year.
We all also have traditional ways of welcoming babies, celebrating marriages, and dealing with deaths.
Traditions help us remember who we are, because they remind us of our past and help us look forward to the future.
While Christmas is the day Christians celebrate the birth of Jesus (even though the date might not be historically accurate) it's also the time when we remember our own families and heritage.
For over a century my mother's family always gathered for dinner on Christmas day, but when including all the third cousins and their kids became to large for anyone to host, we stopped doing that. Now we gather in smaller family groups, but still try to keep in touch with the rest of the extended family at this time of year.
And millions - maybe even billions - of people will have lights and decorations on trees and open gifts on that day.
What traditions do you have as you celebrate?