I believe acting younger than one is and exploring how one felt or acted at a younger age is part of a process, perhaps the therapy process, but is not some place we aspire to "end up". Stopping the train to get out and take part in a Jesse James-style train holdup would overshadow that you are actually trying to get to Chicago? Enjoying thinking and reading about train robbers and imagining what it would be like is different from actually experiencing it "now". Even if you were on a train/plane when someone tried to hijack it ("The Taking of Pelham 123") that past experience is not all of your experience nor is it your "now" experience? Literal re-enacting that experience would be a "new" experience, not the one from the past and might skew the rest of your "now" experience and send it on a different track. It's a re-enforcing experience rather than being helpful?