Genuinely, you should refer them to Eric Wargo's book. They'd realise their experience is not that anomalous - Wargo says precognitive dreaming is the most widely documented psi effect.person had a raft of capital T traumas but it was their dream which confounded reality, as they said “in an aspect of reality”, so your role is to try to talk through consciousness studies and being with a well-read individual and, inadvertently, you get scragged by it too
of a few thousand people seen only one was ever haunted by an actual dream, most were nodding every chance to dream
Obvs only if that's appropriate in the relationship you have.