THE BLOG
07/09/2015 04:31 pm ET | Updated Jul 09, 2016

40 Is the New 20

In some societies, people don't keep track of birthdays and numerical age is meaningless, like in the Australian outback or among Samoan tribes or in the backseat of Leonardo DiCaprio's limo.

I wish that we didn't recognize birthdays here in America. Oh, sure, you'd miss the parties. On the other hand, you don't need "on this date you were born" as an excuse to get together with friends, accept their generous gifts, eat cake, get sh*tfaced drunk alone in the upstairs bathroom while cursing out your friends, sober up the next morning, apologize to your friends for your inappropriate behavior, and post the group pics on Facebook.

Rather, I don't like birthdays because I hate the random, socially constructed guidebook associated with how old you are. Teenagers are supposed to talk like this. Sixty-year-olds are supposed to act like that. President Obama is too young to be wearing those jeans. Caitlyn Jenner is too old to be wearing that dress. Blah, blah, blah.

To quote the dying one-hundred-and-four-year-old woman whose doctor incorrectly told her she had another six months to live, "Life is short." So do whatever the hell you want.

Age is just a number. Only a year and a day separate twenty-nine from forty. But yet what it means to be in your twenties is so much different from what it means to be in your forties. They say that fifty is the new forty. But nobody ever says that fifty is the new twenty... I mean, other than the Real Housewives on Bravo.

The reality is that, biology aside, the life course is pretty subjective. There are twenty-year-olds who are married with a full-time job. There are forty-year-olds who are still in school. There are twenty-five-year-old homeowners. There are forty-five-year-olds who live with their parents.

In fact, even our biological changes are pretty inconsistent. There are twenty-year-olds who suffer from serious illness. There are forty-year-olds in perfect health. There are twenty-year-olds with gray hair. There are forty-year-olds with six-pack abs. There are thirty-year-olds who run five miles every morning; there are thirty-year-olds who are unable to do a sit-up.

Jennifer Lopez is closer to fifty than forty. Lil Wayne is barely out of his twenties. Who looks better? Heck, who looks younger? (Though, in fairness, if you replace Jennifer Lopez with Betty White, the answers still won't be Lil Wayne.)

Nevertheless, everyone experiences and changes and grows. And there are general differences- sort of, kind of, more or less- between people of different ages. Yes? No? What do you think?

When you're twenty, you're competitive. When you're thirty, you're innovative. When you're forty, you're contemplative.

You learn when you're in your twenties. You live when you're in your thirties. When you're in your forties, you learn that everything you learned in your twenties was wrong.

When you're twenty, you say you don't care what other people think about you. When you're thirty, you actually don't care what other people think about you. When you're forty, you finally understand that nobody is thinking about you.

When you're twenty, thirty seems old. When you're thirty, forty seems old. When you're forty, thirty-nine seems so young.

When you're twenty, you're too young to drink alcohol. When you're thirty, you're too young to be President of the United States. When you're forty, you're too old to play the girlfriend in a Hollywood film.

When you're twenty, you love all your friends. When you're thirty, you start to lose touch with friends. When you're forty, you realize who your true friends are.

Twenty-year-old women think that forty-year-old men are too old to date. Thirty-year-old men think they're young enough to date twenty-year-old women, while thirty-year-old women think they're old enough to date forty-year-old men. Forty-year-old men think we're all in the same general dating "age range." Forty-year-old women think that forty-year-old men are too immature for them to date.

Some twenty-year-olds look thirty. Some forty-year-olds look thirty. Thirty is the age when people start looking really good or really bad.

Unhappily married twenty-year-olds get divorced. Unhappily married thirty-year-olds try to make their marriage work. Unhappily married forty-year-olds try to make their divorces work.

When you're twenty, you don't think about your health. When you're thirty, you start thinking about your health. When you're forty, you start thinking about your mortality.

People in their twenties are Millennials. People in their thirties are Generation Y. People in their forties refuse to be labeled.

When you're twenty, you hate your job. When you're thirty, you like your job. When you're forty, you like your job but hate your boss.

When you're twenty, you wear jeans with holes. When you're thirty, you wear jeans without holes. When you're forty, those comfy jeans you still own from your twenties are starting to get holes

When you're twenty, you listen to popular music. When you're thirty, you discover different kinds of music. When you're forty, you listen to the music you grew up with.

When you're twenty, you think about children. When you're thirty, you love your children. When you're forty, you can't stand other people's children.

Twenty-year-old athletes are gifted. Thirty-year-old athletes are experienced. Forty-year-old athletes are "crafty."

When you're twenty, you don't care about politics. When you're thirty, you're interested in politics. When you're forty, you're disgusted by politics.

When you're twenty, you live life without regrets. When you're thirty, you have a lot of regrets. When you're forty, you just live life.