True. What is strange is that a paranoid person such as Stalin actually trusted Hitler and even ignored and threatened his own intelligence services after they warned him of the impending invasion.
Both thought that it would work out for them.
Hitler thought Britain and France would back down once they heard about the deal with Russia.
Stalin thought that it would unleash war in the west where the armies would bleed each other dry, allowing the Red Army to swoop in. He didn’t count on France falling so quickly.