I read in James O'Heare's Separation Anxiety Work Book that this reaction to when we return home is an opposing emotional response to separation stress.
this dissipates over time but does account for the over exited greeting that usually occurs upon returning to a dog who is to a degree reactive to isolation.
As to the retrieved items well we are owned by gundogs after all.
All my three show the crazy behaviour when we are reunited so I guess all three sufer some form of separation stress when we are not together.(I know I do)
My two workers Doug and Bayley always appear with a toy or shoe in their mouths but my old show goldie Oliver just barks and creates a bit.
Something very obvious in the breeding there