I won't say that I don't miss my guys when I'm out and about, but, they are a little bigger than a lot of the pups here on the site. Maybe it's like kids, you sorta trust um more when they grow up, after a point ?
Even though I'm still pretty active, a major part of having my guys here is the security issue. I don't and have never expected or demanded that they rush out and start attacking "an intruder", but, I definitely depend on their eyes and ears, to alert me when anything comes close. And GEES, do they do a good job there !

(generously praised when they get it right)
But to extend that "separation anxiety" a little, I think it's exacerbated by not having your "buddies" watching your back.
I definitely feel better, when I know My Male Sneakers has his nose stuck out the window, in the Car or at the House.