He's just an optimist !
Some dogs do 'never learn'. My mother had a tiny papillon that lost an eye and got a broken rib, among other injuries, in fights which he always started with the Puli and other dogs in the house. To their credit, they tried to ignore him, but every once in a while his attacks got too much for the subject and got a response. In every other respect he was normal, but he would decide suddenly to start an argument just for the hell of it, as though thinking 'this time I'll win'.