Gintoki has left a lot behind, some of it good, and some if it bad. The theme of this anime seems to be about moving on, and not being consumed by the past.
If you compare it to the allegory of the cave, have both Gintoki and Takasugi left the cave and learned the truth? Or has one of them stayed behind, watching shadows and believing them to be reality?
Ugh.... the FEELS.... T___T