No, they certainly can't. They are a part of us forever. Dolly was like one of those dogs that adopts and nurses kittens or tiger cubs. Not once but several times she rescued birds as small as hummingbirds who had stunned themselves on our windows. She'd pick them up, carry them into the sun, and nudge them until they came to. If they didn't, she'd carry them off and bury them in the yard.
That cat's a whole 'nother story. I'm sure you've seen my pictures of her playing guitar with me, but here's another one.
We do that daily, several times. She's glued to my hip, but is careful to assert her independence - e.g., she sleeps at my legs every night, but doesn't come to bed until she thinks I'm asleep, and jumps down at my first stirring in the morning. Typical female.
Thanks, man. There's no formula. I've found I simply have to let these things change me, and only keep people in my life that can keep up with the changes. Thank goodness, Riverette is one of them (and vise versa).
This says it all about Dolly. She was everything a man could want in a dog, except a watchdog (she was great at guarding us against bears, cougar, etc., but couldn't bring herself to be aggressive towards a human to save her life).
You had one hell of a dog too. They teach us more than we teach them, don't they?