I got married relatively young to the brother of a best friend and the man who would become the light of my life.

In the years leading up to my debut in white satin, I avidly consumed reams of advice on the perfect marriage. Of course, since it was all largely irrelevant, it didn’t mean much to me, and didn’t quite penetrate.

Out of the multitude of tips, anecdotes and chronicles of suffering, I was left with but one ridiculous gem of information: Couples often fight about the toilet seat being left up.

Perhaps due to the surprising reactions to (what I thought was) an inconsequential matter, that little detail stuck with me for all those years.

And then, under the wedding canopy, I agreed to make this marriage work.

Admittedly immature, I was thrust suddenly into the uncharted territory of living, loving and accepting another human being—completely. I knew it would be tough, although I had no inkling of quite how tough. I knew it would be a challenge, demanding and draining, but ultimately gratifying.

I knew I couldn’t promise to make his needs my needs. That’s too grandiose a project for a slightly selfish young woman with the maturity of a girl. But oh, I wanted to reach that peak of marital bliss, that wonderful feeling of giving everything to the one you love. And I certainly didn’t want to be the one fighting over toilet seats.

So, I made a resolution. It was a small one, and I didn’t even tell my husband.

Whenever I left the bathroom, I left the toilet seat up.

And that small conscious act of putting his needs before my own made all the difference.

The Rebbe said that it was better for someone to give a penny or two a day than to give a dollar once a month. True, the amount given to charity may be the same. But through those pennies, you make yourself into a giving person.

It’s hard to understand how a minor act, repeated often, can change a character trait completely. But it works.

The Tanya says that “habit becomes second nature.” And it doesn’t limit itself to negative behaviors. A single positive habit can overturn years of destructive ones. Light has an innate advantage over darkness, and even in small quantities it prevails. Adding just a pinprick of light changes the entire scenery.

My toilet-seat resolution gave me a certain confidence. I was now doing something concrete to make my marriage better. Perhaps it gave me too much confidence, and I began attempting a new skill. I should have known better.

I can’t cook. I mean, I’m not one of the completely inept can’t-follow-the-directions-on-the-back-of-the-box-of-noodles people, but I don’t have much luck in cooking. To my credit, I tried. My mother graciously gave me of her time and wisdom in trying to teach me simple but appetizing foods.

Okay, so it wasn’t a complete disaster. But it took so much energy out of me, I couldn’t keep it up. I started letting my husband make himself scrambled eggs for dinner. Thankfully, he didn’t let on if he minded. And he stopped expecting hot meals.

One fine day, we got into an argument. It was one of those big ones that only newlyweds can manage, where you’re furious, but it’s futile because the whole disagreement is entirely based on a miscommunication.

So he left the house upset, and I paced the apartment, muttering to myself about how impossible men can be. I was too worked up to spend time on any computer tasks that required mental energy. That’s when a small glimmer of maturity shone in my mind. I made supper.

I think that night was a turning point for both of us. When he came back, I was in the kitchen. I came into the dining room to see him staring, shocked, at his plate. Still a bit angry, I snippily asked, “What are you looking at? Is there something written on the plate?”

“Yes,” he answered. “It says you still care about me.”

That moment made it clear to both of us: I’m committed to you, and you’re committed to me, and an argument won’t change things.

But the best thing for me was to realize that I am more than my emotions here. I can take a loving step even when I’m furious. Whether that’s writing a note, cooking something or straightening up, it reminds myself that the anger will pass, but not the relationship.

The great Maimonides says that we should look at the whole world as if it’s a perfectly balanced scale of good and not-so-good deeds. A single positive act takes the world out of equilibrium and puts it squarely into the category of good.

It changes more than just me or my marriage. It changes the world.