As we get into our late teens and early twenties, “No” slowly starts creeping into our lives. It is gradual, but its presence becomes very real with time.

“No” begins popping up here and there.

Remember that time when you and “No” told your best friend you couldn’t go downtown for his 21st birthday because you had a test?

Or that time you and “No” told your cousin that he couldn’t crash on your couch over the weekend? After all, you were going out of town and you hadn’t spoken to that guy in years. (He contacted you out of the blue. How were you supposed to know he wasn’t just there to rob you?)

We start to carry “No” like a burden. We become producers of “No” in addition to consumers—albeit, begrudgingly. We use it, but sparingly—and we still wince when we see it hurt others.

As time goes on, we start to shut others out more and more. The pain of saying “No” begins to dull with time. It is still scary, but also exhilarating to finally be able to confidently say “No”—that once dirty word that used to make you sad when you were a child.

One day we realize that “No” doesn’t have to be a sacrifice—it can be a source of freedom.

We begin to experiment further with “No.” It slowly dawns on us that “No” can be more than a way of sacrificing fun for work; it is an important tool in maintaining your personal boundaries.

Eventually you look around and realize that success is largely based on the ability to say “No” to others. Saying “No” is sometimes the only way to make room for your own interests. And often that comes at a cost.

You see friends being overworked because of their inability to say “No”—their desire, but inability to please everybody. Their boundaries are invaded, and their resources are spread thin. They struggle to keep up with the demands of their many commitments, and that struggle eventually turns to suffering.

It is crucial to be able to deal with “No” in your life.

It will be very difficult, but you must overcome the difficulty of saying “No” to those trying to invade your boundaries. You must be able to hold your own against these people—and often they will be family, close friends, or people you trust. People you don’t want to disappoint.

Let me tell you now, in case nobody has told you before: It is okay to say “No!”

It is okay to say “No” to that shaky investment opportunity your old friend from high school is pitching you; You don’t owe him anything just because you took AP History together. And even if you do owe him, you are still allowed to say “No.”

It is okay to say “No” to your neighbor who is asking for donations to fund an obscure charity run. And it is perfectly acceptable to say “No” a second time to that same neighbor’s children when they come around selling you popcorn and Girl Scout Cookies. (If you watch what you eat at all, then that last “No” should be an easy one.)

It is okay to say “No” to graduate school.

It is okay to say “No” to buying a house.

Hell, it’s perfectly fine to say “No” to buying a car! Go buy a good road bike and get a workout on the way to-and-from work!

Say “No” to the life others are trying to tell you to live. You don’t need to be married by 30. You don’t need to have children. You don’t need to go to college. You can choose to say “No.”

When I began submitting my writing for publishing, I began to re-acquaint myself with “No”—from the receiving end.

My first time trying to get published, I sent out four or five articles to a dozen different potential publishers. I received uniform, unanimous “No’s” across the board. It was a blow to my pride, and it took me a few days before I could summon the willpower to even keep writing and submitting.

Let me tell you something now: even though you might get used to saying“No,” you will never get totally used to hearing “No.” Rejection hurts no matter how old, rich, or famous you get. I think that’s a universal truth.

Every “No” still has a sting. I like to think of each “No” like a needle.

If you lie down on a single needle, it will hurt tremendously—because the pain will be concentrated on one spot coming from one source. But if you lie down on a bed of thousands needles, even though there are many more, the pain is less because it is spread out and no single needle’s pain is overwhelming. So it must be with “No” and you.

Keep trying, and keep getting rejected. It will give you the thick skin you need to make it. After enough perseverance, and countless “No’s” you will find yourself face-to-face with a bonafide “Yes.” And then, doors will open for you.