The more people you see each day, the more you will be asked a version of "How are you Doing"?
How's it going, how's it hanging, wassup, etc. Of course, it's what we do. I usually like it. Heaven knows, let someone walk by you without some sort of greeting and you'll ask yourself, "What's up with them? They might be having a bad day, or maybe their upset with you. And away your mind goes for 20 minutes thinking, "Now what did I do"?
No, it's better off to just greet everybody and yes, ask them how they're doing. A few of us might even tell you the truth, skipping conventional responses, if we feel like whale scat, we'll tell you. If we feel like a million bucks, we'll tell you.
My latest response has been "Mostly Sunny" Both true and descriptive, mildly engaging. I'm looking for a new one. It's been rainy of late. "Right as Rain."
When you ask me next time, How I'm doing? You probably already know the answer.