In the summer of 2013, when I first started running, I also did Jillian Michaels’ 90-Day Body Revolution video series. Thirty minutes every day of high-intensity circuit training, on an exercise mat, with free weights and a resistance band–just me, alone with Jillian, in my bedroom in our Georgetown basement apartment.

Jillian shouted all kinds of motivational cliches at us, and in the moment, when I heard them, I didn’t think about them too much. But thinking about them later, I realize how true they are. One of her sayings was “What you believe, you achieve.”

I didn’t really understand this outside the context of exercise until recently. But it’s true. If there’s something important or hard you want to do, you have to first believe that it’s possible for you. That’s all. Simple, but maybe not always easy. Your belief in your ability to do the hard work, your sense that you deserve whatever success or satisfaction will come of it–these are the key foundations to anything you want to do that you’ve been putting off for whatever reason.

I didn’t actually start doing the work to achieve anything I wanted until I believed that I could. And you know the rest. She believed she could, so she did.

And one other thing: don’t tamp down and deny your own feelings and aspirations and interests in order to make everyone around you feel more comfortable. I’m still working on this; there are a lot of scripts in my head about how much space I’m allowed to take up, what it means to be likable, and the most feared descriptor of them all: selfishness.

But denying yourself for the ease of everyone else in your life is a sure path to all kinds of bitterness, regret, and in my case as a teenager, depression. It’s okay to be sad, lonely, restless, angry. We are only human. You don’t have to be all smiles because it makes things easier for everyone else. You can say no. You can quit if you change your mind. You don’t have to “have it all” or be perfectly “balanced.” The people who love you will stick around anyway. And you might actually find that you love yourself.

Of course it’s important in relationships to account for the other’s needs. But don’t forget your own.

I told my therapist that I didn’t feel like I figured out I had a personality until I was in my thirties. When you learn at a young age how to perform–just how to be to ensure everyone around you is applauding, how to tiptoe around to keep the waters calm, you become like a chameleon. You blend into the environment to suit everyone else. But as time goes by, an insidious process happens whereby you actually do forget what you want and what you like and who you are.

But life is short and as far as I know, we only get one. We will all die someday. Why are you wasting time–filling time–with things you don’t care about? Acting nice and spending time with people you don’t even like that much? Finding reasons and excuses to put off doing the things you really want to do?

No one is going to show up at your door and offer you the things you so desperately want. You do have to do the work and be accountable to yourself. But doing so will liberate you.

Here’s a reminder from Louisa May Alcott’s novel, Moods, which I am writing about for my dissertation:

“She tried heartily to forget herself in others, unconscious that there are times when the duty we owe ourselves is greater than that we owe to them.”

Even in 1864, women knew.