It is because anything with your smell on it reminds him of you. Make sure he is confined to an area (one room, or a hallway) where he cannot chew anything other than what you have given him to chew, i.e bones, pigs ears, a treatball stuffed with treats, a kong stuffed with peanut butter or anything else he likes. Make sure he cannot chew any electrical wires or telephone cables. Also make sure he has had a good walk before you leave him so he will want to sleep while you are out. You could leave him with the doggy equivalent of a comfort blanket, i.e.
or old sock, and rub your scent on it. He is still a baby in Rottie terms, so don't be cross with him, be cross with yourself for leaving stuff where he can get it!