As given by my name, I am an uncle, both in the familial sense and the friend sense. Allow me to explain.
While I haven’t seen many of my family members for years, I have become friends with a person who calls me “Brother” and I call her “Sister”, and collectively I am her son’s “Uncle”. (It’s actually uncanny how alike we are that we *weren’t raised together, based on our beliefs and quirks). We live in the same condo building. There is another friend of the “family” who lives in our building. We have all known each other for 10+ years, so he’s an “Uncle” as well.
Recently, we were all sitting around watching football and discussing an interaction I had with her son. I was fortunate enough to be waiting for the bus with him for approx. 40 min. (Yeah, tell me about it.) But, honestly, he’s a great kid (15 yo) with a good head on his shoulders. “Sister” asked me to discuss our conversation with her because “nephew” asked her if he could discuss our discussion with her. So her interest was piqued and wanted to hear my side of the story. Once she heard, she asked "Uncle {Brother Walker} and Uncle {our other friend} to step up and talk to the boy as he transitions into manhood.
I gotta tell ya, I felt really proud. My friend wants me (and my other friend) to talk to her young son and give him advice about life, college, and the big picture in general. Believe it or not, SOMEBODY IS TRUSTING ME WITH THEIR KID! (I put that in caps because although I’ve come from a not-so-great background and actually didn’t turn out to be a total jerk in my life (although I’ve had my ups and downs), my friend thinks enough of me to advise her child about “how to do it right”. Brings a tear to my eye.
So I plan to spend as much time with the kid as I can, when he’s around. He’s recently taken it upon himself to get a job, so he’s not a home as much as I am anymore. I love this kid.
Okay, sorry for the gushy hijack, but I wanted to say it. Now back to the OP:
I also consider the “Uncle” title an honorific. It means the kids like me in a special way. Again, not having had any family contact for years, it makes me feel good. When I meet “nephew” on the street, as happens more often than not, I always address him as “Young Master {name}”. He doesn’t understand what that means yet, but I’ll train the boy yet. He addresses me by my first name, but his mom talks to him about me as “your Uncle Walker” (The “brother” is considered as a given).
As a southerner, I agree with the Sir/Ma’am title. If there is no relationship previously, this is right. If there is no relation, it’s Sir or Ma’am. If there is, you can go many directions. You can say “Mr. Paul” or Miss Ellie" (especially in TX), or you can go “Uncle or Aunt” Billie. I think it conveys a sense of love and trust from the child to attach a title that is more familiar than formal.
Bottom line: Yeah, he’s a prick. But again, Lighten up, Francis.