Growing up in the USA the typical greeting was a quick hello, a handshake, a nod. But, here in Mexico it is more customary for people to take the time to stop, say hello, give a cheek kiss, a hug, etc. You are actually a rude if you don't acknowledge the person.
Sometimes I mess up. I get in a hurry or am in my own little world and don't greet someone. I am sure my face turns red when I realize that once again I broke the greeting etiquette and slip back into my American ways. I am a work in progress, i guess.
It is not just the greetings that are different, but also the goodbyes. You can not just say a blanket goodbye or open the door. You need to again go around to everyone and give individual goodbyes.
For an american who is always in a rush and focused on the next task, I find this way of living to be refreshing. It causes me to slow down. To enjoy the people and the relationships around me. People are truly acknowledged, like they should be, instead of a quick exchange that barely makes notice of the person.
Greeting people, as I have come to realize, is important. People are not meant to be overlooked and you shouldn't be too busy to invest in that relationship.