Spring is a special time of year for many reasons. While the season signals new beginnings with fresh flowers, it’s also a time for endings, such as the end of the school year.

Preschoolers graduate to kindergarten. Elementary students graduate to middle school. Middle school students graduate to high school. High school students graduate and follow life’s trail to college or the working world.

Graduation is a joyous time to celebrate the milestone of academic achievement. It’s a time for family and friends to gather together to show how proud they are of what the graduates have accomplished.

The graduation ceremony is a rite of passage that creates lifelong memories. If you’ve ever attended a graduation ceremony or seen pictures of one, you’ve surely noticed that everyone seems to be wearing the same outfit.

And it’s not your normal everyday clothes, either. So what’s the deal with the robes and the funny hats?

Those funny hats are called “mortarboards” because they resemble a tool used by bricklayers to hold mortar. In some areas, they’re also called “square academic caps” or “Oxford caps.” The mortarboard consists of a flat, square board attached to a skullcap, with a tassel buttoned to the center. Scholars believe the mortarboard is based on the biretta, a similar hat worn by Roman Catholic clergy. The biretta was commonly worn in the 14th and 15th centuries by students and artists.

Mortarboards are paired with robes to form the traditional graduation outfit known as “cap and gown.” Formal or “dress” clothing, such as a suit, is usually worn beneath the gown because graduation ceremonies are considered special occasions worthy of formal dress.

The cap and gown combination can be traced back to the academic and clerical dress commonly worn at the medieval universities of Europe.

These early universities didn’t have buildings, so students would usually meet at churches. Since these churches were unheated, historians believe students wore long gowns and caps for warmth.

Some children are curious about the tassels that hang from mortarboards. In some cases, the color of the tassel matches school colors. At other times, special tassel colors are used to represent particular degrees, subject areas or achievements.

It has become a tradition at many schools for all graduates to wear the tassel on one side until receiving their diplomas. After the graduating class is announced, the students then switch the tassel to the other side. After switching their tassel, many graduates also toss their caps into the air to celebrate.

The hat-tossing tradition got started in Annapolis, Maryland, in 1912. That year, students at the U.S. Naval Academy became officers for the first time (instead of having to serve two more years as midshipmen) and flung their hats into the air spontaneously.

Since that time, the tradition continued each year, and it has become a ritual at schools — even elementary schools — everywhere!