On Friday, my 6-year-old woke up with a stomachache. He stumbled into our bedroom and began groaning.

“Can you go to school?” I asked.

“No. I don’t feel well enough,” Andy said, and proceeded to pass out atop his “Star Wars” sheets for four hours. And that was that.

A couple days later, I asked if he wanted to have a play date with a friend down the street.

“Not right now. I want to play Imaginex,” he said. Simple enough.

Meanwhile, I was feeling frazzled and overcommitted. I’d promised a friend that I’d edit her resume. I’d promised someone else that I’d bring over bagels. I signed up for a volunteer activity at Andy’s school and completely forgot about it, bought an elaborate set of Valentine’s Day crafts that were quickly going limp on my dining room table and promised someone else that I’d pick up her kid from school while she was away, even though I really didn’t have time. Oh, and work, of course.

That’s when I realized that I needed to take a lesson from my 6-year-old: Just say no. He didn’t hem and haw if he didn’t want to do something. He didn’t torture himself with guilt, overcommit and then become resentful and frazzled. It was all so simple and clear-cut. Sure, there are some things that we have to do (hello, work), but there are some things that are just plain extraneous and stressful. Yet we do them anyway.

I know I’m not alone. Most people I know stretch themselves too thin, fail to set proper boundaries and end up spiraling into an anxious mess. I asked a few fellow parents why. Why is it so hard to say no? Some answers:

We’re afraid of disappointing people.
Most of us are hard-wired to seek out reassurance. We associate saying no with letting someone else down. And who wants to do that? It’s easier to say yes and get the immediate gratification of approval than to say no and risk a confrontation, even though this will probably never happen. Honestly, who would get mad at you if you couldn’t bring them bagels? Nobody you’d want to know.

We want to appear “together.”
We associate being busy with self-worth. The more we take on, the more capable we are. This is painfully untrue, of course, as anyone who’s tried to conduct a conference call from a piano recital might tell you.

We mean well.
The school rummage sale? The friend who needs a favor? We want to help out! But our goodwill doesn’t match our reality.

We don’t know how to politely decline.
A lot of us just don’t have the language to say no. We stumble and stammer and make excuses and fall all over ourselves apologizing. It’s awkward and uncomfortable. “By the time I’m done trying to say ‘no,’ I’ve actually said ‘yes,'” one friend told me. Yup.

So next time I’m tempted to do something that I just don’t have time for, I’m going to try to act like a (slightly more mature) kindergartner. I’m just going to say, “No, I can’t do that. I’m sorry.” It’s going to be scary and hard. But I think it might pay off in the long run. I’d love to hear from others who’ve mastered the fine art of boundary-setting. Any tips, tricks, lessons? Let me know. Or don’t. You can always say no.