"Humility is no substitute for a good personality". ~ Fran Lebowitz, Metropolitan Life, 1978
Have you ever walked into a restaurant or a store and as soon as you walk in, you say hello and everyone within an earshot says hello back? In the United States, this is highly uncommon. At most, you may receive a random greeting in the form of a smile, or a welcome from a store or restaurant employee.
In Mexico, it is actually considered rude to enter an establishment without greeting those inside. The type of greeting you give depends on the time of day. Good Morning [Buenos Dias], Good Afternoon [Buenas Tardes], and Good Evening [Buenas Noches] are proper salutations. Not only can these be used when saying hello, but they are also a way to say good-bye.
There's something nice about being greeted not only by store or restaurant employees, but also by other customers. It's as though people aren't too busy to take time out to say hello. It might not seem like much, but I really appreciate being greeted with such kindness. When I'm in the U.S., I find myself walking into stores wanting to greet everyone but if I did, I'd probably only receive confused looks in return.
Being humble is an awesome quality to have. Having a nice personality is great too! Most people in Mexico seem to have both. When you come to visit, please be sure to give saludos a todos!