“That’s a big dog”

I have a 70 lb adolescent rescue dog. He’s close to full grown. The entire community and general public will not stop commenting how “BIG!” my dog is.

He is smaller than most goldens and labradors, who don’t receive this attention. I’m not taking him on an airplane, we’re just walking down the street. He comes up to just above my knee.

Why do people say this? Do they not know what to say? Are they uncomfortable with mixes that aren’t small? It seems like they are not happy about the dogs size.