Maybe before he had started his session he might have believed time travel were not possible. Well, no. He'd believe it. Crazy shit has happened and he wasn't really going to think it was plausible. It just became really possible when the session started.

'yea ok
time travel isnt a thing
were all drugged as fuck on this train to fucking nowheres land
thats all
btw
did you even read the shit in your bag???
just curious
its a fucking amazing read i gotta say'

He shook the schoolbag that he had. This wasn't his before, he just had it when he was conscious enough to notice it.