Some people are more comfortable saying hi to *anyone* than others are. How many times are you in a grocery store that people you *know* saw you pretended they didn't? Heck, I think I look pretty normal, LOL, but I just assume people either are in a hurry, don't care to talk at the moment, or just aren't comfortable for whatever reason. No big deal. Papa Deuce, what do you normally do if you're in a rush in Costco and don't feel like talking to someone you know? Was not saying hi to this guy out of the ordinary for you - i.e. had he not looked the way he looked would you have said hi?
Does anyone here remember the thread not to long ago about whether you would say "hi" if you saw someone you knew to be another Dis-er at WDW? I was surprised at how many said they would not say hello to other Dis-ers!
I live about an hour from where I grew up so I don't see friends from the past too often (other than the ones I've remained close with). I am the type of person that enjoys people and likes to talk regardless of what people look like, smell like, sound like, act like, etc... (but then again, being a nurse, that's just me - my own DH is just the opposite).
Placing myself in the situation you've described I think I would have more than likely said hi (unless he exhibited signs of instability or major mental illness). I wouldn't assume anything about him but if his appearance was disheveled I'd probably ask "how are you doing" and see where that leads. Maybe there'd be something I could do to help in some small way or somewhere I could refer him if he really did need help, who knows. Sometimes just a little thing can make a big difference in someone's life.
Recently, someone I knew from high school died of a heroin overdose. Tragically, photos of his shooting up in public, then collapsing and dying were published on the front page of one of our major newspapers. It bothers me a lot to think about what a dynamic and handsome individual he'd been in high school and what had happened in the years since then. I thought how sad it was he didn't get the help he needed before this tragedy occurred. People need help sometimes, and it doesn't always come from those you think will provide it.
Two more thoughts while reading this thread. One - I went through a full course of chemotherapy (with hair loss and all) and didn't look like "death warmed over". In fact, most people had no idea of my circumstances unless I chose to tell them (LOL, talk about making someone uncomfortable

SURPISE, I may
look normal, but I have CANCER

[insert squirmy/too bad you didn't keep walking smilie here] ).
Secondly, don't most of us talk about money here on the Dis? How do we get the best deal at a WDW resort? How can I save on booking a cruise? Can I re-use the mug I bought in 1999?

That's what brought many of us here in the first place. And for a grown man supporting a family and thinking about all there is to think about financially in this world, to me it's not unusual to think the way Papa Deuce thinks. There is another poster that I can think of that posts the same way, so what. We all have our particular interests and personalities.
Lastly, I remember a lot of weird details about my high school buddies. We were into cars in my family and I definitely would have remembered a car costing that much seeing as that back then it would have had to be
some car!

(I myself was driving my $500 Torino in the 70's

).