It doesn’t seem like the torah learning is a [burden] to you, just the weight of a sefer.
Exactly. I don’t see the equivalence between the learning and the shlepping. Does a guy with a regular sized Artscroll gemara volume get more schar for learning than a guy with the smaller “daf yomi” volume?
In this case, I would have ended up learning the exact same amount — I just would have gotten to the stopping point a few minutes later in my ride.
Assuming that the 10 minutes later train doesn’t magically reach your destination sooner than your normal train, you may well have had an opportunity to learn more than you would have otherwise. I think you did the right thing with your inner critic. 🙂