Lever 2000, Head & Shoulders, Gillette… Edge, Old Spice, Mennen Speed Stick… Kellogg’s Raisin Bran, Deitz and Watson, Dijonnaise… Folgers, Splenda…and where the heck did I put my watch?

Every morning it’s the same dance: I shower, dress, eat breakfast and head to work. All while interacting with at least 30 brands just to get out the door. And every one of those brands is a repeat purchase; many going back so far, I don’t know the last time I bought something else. Yet change just one of those products—or run out of one—and the morning routine is disrupted. Perhaps I stop and make a note for a shopping list, or, if desperate, launch a mad search for a replacement.

One of my favorite questions to ask in brand development sessions is, “What toothpaste do you use?” Everyone can answer that question in a second. “How long have you used it?” Typically longer than they can remember, dozens of tubes of toothpaste—maybe hundreds—slowly squeezed to death. Nearly all them bought without much conscious choice. The brain says, “That’s right, I need toothpaste,” and the body heads down the toothpaste aisle to get the same brand again and again.

How easy is it to change brands? Seems pretty simple. You reach a few inches to the left or right on the shelf for a different toothpaste brand, for instance. But what’s even easier is not changing. I haven’t given my toothpaste—or dozens of other brands in my life—a second thought in years. It’s easy to buy what works just fine. And it means not having any apprehension about my choice of brands.

Each of these products has an army of people who have built the brand and are taking it to its target market. They spend their days (and some nights and weekends) fighting for additional market share. I haven’t spoken to anyone at these companies, I haven’t used a coupon. I haven’t been to their Facebook page, or liked them in order to enter their contest. But I keep buying their products and paying premium prices for them, even though I could spend less on the store brand if I wanted to.

Think of the power of this unconscious brand loyalty. And think of the difficulty of getting a person to change. Back to my toothpaste example: I will often follow up with another question, “Why did you first buy this brand?” Again, memory fails all but the most ardent participants. “I grew up with it.” Or, “My dentist said to use it.” One example was “My medicine cabinet was so small that I only had room for a tube that would stand on its end. Colgate came out with that and I’ve used it ever since.” A small advance in packaging technology created a lifetime user of the product.

Of course, the loyalty to a packaged goods brand is one thing—just keep making it exactly the same and you’ll probably keep my business—but loyalty to more complex brands, such as services where repeating the brand experience is dependent on a changing roster of clerks, customer service specialists, salespeople or account executives, is quite another. Here the use of the brand is likely to be more intermittent, to cost more than a tube of toothpaste, and to have far more chances for a glitch in the process. My dry cleaner lost a shirt one time. No big deal, it was an old shirt and they gave me a little credit back. Then they lost six shirts and a pair of pants and asked to see my claim ticket to prove I brought them in. Too-da-loo!

So somewhere between mindless loyalty and total failure to perform is the sweet spot that brands fight over as they try to grow and expand their reach. Brands often look for a tiny foothold to get your attention—a new flavor, a new package, a brand extension aimed at expanding sales among current loyalists. Apple builds amazingly innovative new products, reinvents them almost annually and sells last year’s model at half price. That satisfies both the loyalist and new customers who are looking for a cheaper way to own an iPhone or iPad.

The next time you want to understand your company’s brand a little better, ask yourself why you use the toothpaste you use, why you shop at certain stores and not others, and the reasons why you changed brands for anything. In those answers you may find some insight into creating new customers and into building automatic loyalty with your existing ones. As the management guru, Peter Drucker, once said, “the purpose of business is to create and keep a customer.” Not coincidentally, the very best brands are quite good at doing both.