Wellll, in the dreams I'm kinda sorta a soldier in this huge army, the First Order, that's trying to take control of the galaxy and crush the Republic and its Resistance that's running it? Basically, we're the bad guys.
Except I deserted, ran into a Resistance pilot, crashed onto a planet with him, thought he died, ran into Rey and said pilot's droid who has information that needs to get to the Resistance. I lied to Rey because BB-8, the droid, thought I'd stolen Poe's jacket, which was the only thing I could recover from the crash. He's the pilot. So before I got the crap kicked out of me from the both of them I said I was Resistance too.
And yeah, it sounds like Solo's had plenty of experience.