To SPs,
Let's say you have a regular client. You run into them out in the wild and are alone (not with friends, kids, significant others). Can they say hi or come up as a friend would or hell no stay the f away?
When I am in my own head, I am clueless about people in my surroundings. Not only might I not see them, it might take a moment to realize this is someone I should recognize. I have even walked past my own mother in the streets without recognizing someone I knew passed by.
Or
I wave and smile to strangers all the time. Some just faces I have seen for many years and never spoke to. It doesn't cost anything to offer people a genuine smile, and I have been told how it can even brightens someone's day. So if the simplest way I can make someone I don't knows day brighter, is a smile, and a "Have a lovely day." Sounds simple enough to me to get someone else to smile.
But to just come up to me if I haven't given off the impression I recognize them, or am open to conversation, could lead to awkward moments. I am used to people I don't know staring, or having polite greetings. I seem to give off a very approachable vibe, WHEN I am out of my introverted mind, I am a social butterfly.