I know how to do something halfway. It’s so easy just to phone it in, to do as little as I can get away with, especially when I’m facing competing requests from my job, my family, my scout troop, my church, and my doctor. Especially when I’m feeling overwhelmed and thinking it will take longer than I have to give even one task my best effort.

But I haven’t reached the level of professional success I have by doing as little as I can get away with. I haven’t stayed married to my beautiful wife for 19 years by giving less than my best effort. I haven’t beaten cancer by phoning it in.

If it’s worth doing, it’s worth doing well. We’ve all heard that, usually from mothers disappointed that our room-cleaning technique was to shove everything under the bed, or from fathers who had no sympathy when they sent us back to cut the grass yet again because it was still uneven.

Of course, life is a little different today than it was thirty years ago–it’s much easier to become overwhelmed, to sign on for more than we can possibly get done. So I’ve discovered I have to amend the saying. Today, when I have to remind my kids (or myself) not to phone it in, I say if it’s not worth doing well, it’s not worth doing.

The difference is subtle. Our parents told us since you have to do it anyway, you might as well give it your best. I tell my kids don’t commit to doing something you can’t give your best to.

Of course, there are those tasks in our lives we don’t think we have a choice about. Those are where it’s most tempting to give less than our best: the ridiculous request from our boss, our spouse’s demand for help on something we don’t understand the need for, our kids’ pleas to read the book one more time.

We always have a choice. We can say no to any of them–our boss, our spouse, even our kids. But we want to avoid the consequences of saying no, so we say yes and do as little as we can get away with.

Here’s the secret: saying no more often, agreeing only to those tasks we can excel at, does more good for us than saying yes to too much. Distinguishing ourselves by doing a few things well is better for us than doing many things poorly.

Give it a try today. Say no to one task you might be tempted to say yes to–then use the time you gain to excel at something more important. You might just learn something about yourself. Keep it up long enough, and you might even discover your life, your job, your family start to reflect excellence back at you.