If you are a conscientious car owner, you know that in addition to regular oil changes and tire rotation, it's important to get your car's alignment checked. The reason for this is simple - if your car is out of alignment, it means your tires aren't contacting the road the way they were designed to. Driving a misaligned vehicle will wear out your tires extremely quickly. If your car is badly out of alignment, you can actually hear it - the tires make a lot of noise, and that's a bad sign.
How about your shopping carts? Do the casters on your carts make a lot of noise? Do they wobble back and forth when they roll? And worst of all, do you go through a lot of wheel replacements every year due to tread wear? The cause is the same as in your car - poor alignment.
I often find myself getting a little anxious in a grocery store, especially if it’s crowded, and doubly so if there are samples, Girl Scout cookies, newspaper subscriptions, or credit cards being hawked by vendors. The combined noise of shoppers, store personnel, music, public address, and rattling metal carts can put me on edge and makes me want to get out of the store as fast as I can. (I like to shop very late at night if I can because I know that it will likely be quieter and less crowded.)