My dogs like resting their heads on things when they sleep...I'm guessing Zach uses your pillow like that purely because it isn't already occupied by your own head.
I never really thought about first/last name discoveries when sniffing. I think dogs just like checking out good smells and the smells are different at different places on the body. Most of the sniffing I witness is purely back end. Sunnie doesn't sniff other dogs all that much and only the back end when she does. She, on the other hand, is the recipient of a lot of attention back there...doesn't mind at all...but I never considered exactly what area was being sniffed at any given moment. Dan doesn't want dogs coming up to him so his privates are off-limits. I don't remember much about the sniffing activities of previous dogs except Hershey...as a recipient...and only in the instance of one particular dog. He had a Rhodesian Ridgeback friend starting when that dog was a puppy. I used to think he looked up to Hersh as a role model and wanted to get all the information he could. He spent all his time "underneath"....like a car mechanic under a car up on a lift...it was funny. As he grew older, Hersh would actually be elevated by this to-be very tall dog. Hersh didn't care.