On your birthday, you are the queen or king of the world. You can do no wrong, your friends bombard you with gifts, money and free pizza. Don’t like the song that’s playing? Birthday veto!

So what is it about a birthday that makes us feel so special? Several religions celebrate the birth of their founders ‘ the most obvious example is Christmas ‘ and even more associate birthdays with certain rites of passage. Were you bar mitzvah-ed at age 13? Congratulations, you are now officially a man!

Perhaps it is rooted in religious history, but birthdays have now become more than just a spiritual debut. Our age determines many rights that we may (or may not) have depending on how many birthdays we have celebrated.

In the United States, you need to be a certain age to get a driver’s license (this varies by state). When you hit 18, you are officially an adult (by U.S. law, not Jewish scripture) and you can enlist in the Army and cast a vote. The big 21 ‘ probably the oldest age you consider until you actually hit 21 ‘ brings with it a world of legal boozing.

But does your age actually indicate readiness for lifestyle changes? Traditionally, there have been certain justifications, varying from comprehensible to vague, for regulating things such as buying a bottle of tequila and voting for the president. State laws will even tell you when you’re old enough to do the dirty.

The list goes on: labor laws, wage laws, parental laws. Yes, your parents govern you based on your age. Did your curfew change when you turned 16? What about when you started college?

Age tries to neatly define when a person is mature enough to take on responsibility and become accountable. This trend exists throughout religion, culture and politics, making it extremely difficult to escape the deep generalizations that can be found within these familiar standards. Hell, JFK was legally old enough to be president and the American public was still skeptical about his propensity to run a nation.

In age there is symbolism. Little kids don’t know better, teenagers don’t want to know better and middle-aged 50-somethings shouldn’t be parading around in tube tops and short skirts ‘ even if their body still looks like their 18-year-old daughter’s.

Why does an age, a number, a period of time for which we have existed on Earth, hold so much magnitude? Here’s a better question: What else could be used to set this type of criterion we so heavily rely upon across the global social spectrum? This is not to say that I believe such an arbitrary number should be so significant, it is merely that I do not have a better answer.

Being 20 does not feel any different than 19 did, but now I’m not lumped in with 13-year-olds. The indistinctness of age does exist. We feel it every day and every birthday. It is the best demonstration of how things change slowly over time, but it is also the best expression of how something can transform swiftly, and without much effort at all.