This one is another personal favorite of mine, and I think it's a good representation of what Sinnoh is about. Ash's reaction to the young kid crying over Team Rocket capturing what should be his Yanmega is pretty unexpected: he tells the kid to stop crying for the reason that the kid can't be discouraged over something like this. And Ash doesn't mean Team Rocket is low-down and not worth the effort; what he means is life is full of difficult challenges, and as a trainer, it's important not to be discouraged. The writers, by showing this little kid's dismay, are showing, by contrast, how far Ash, Dawn, and Brock have come as trainers. Well, definitely Ash and Brock, we already knew- still nice to see the Caterpie memory, though! I think the important thing is that this does put into perspective the seriousness of the doubts Dawn has had recently. The troubles the kid faces in this episode don't really compare; and that's, I think, what Ash hints at when he tells the kid to be strong. Maybe as a sort of apology for this, Ash shows the kid his badges (as well as Dawn showing him her ribbons), and all three of our heroes show of their pokemon to the kid, to make him feel better. They stick with the kid until he catches his own Yanma, and, as the narrator says at the end of the episode, they feel pretty satisfied they made a difference in the kid's beginning journey. I remember when I first watched this episode (which I can't say for many episodes), and the reason I remember this one is b/c of what Ash said. He didn't tell the kid that Team Rocket are jerks and they'll get in trouble or something (they, of course, do not get into trouble); he told the kid these things happen, and he has to learn to accept them w/o giving up or being upset about it. And that's a very realistic moral.
Yikes, though. Ash didn't have to be mean to a kid right after I said Sinnoh Ash tends not to get onto people about their faults. Kids are more impressionable, and maybe he felt it was important to be firm here. He rarely does this, from what I remember.
Tomorrow will be a fitting episode to look at, heading into Thursday's new episode where Ash and Paul start their Sinnoh League Battle. The beginning of the end of Sinnoh is almost here.