Well, I guess I can't say I'm surprised that Ash didn't remember Serena, But not exactly how they met - though it does make sense.
Horray for the return of serious battle training. It seems Ash and Alexa trained for hours until dinner time, then into nightfall. I hope this continues.
Loved the way Bonnie got tired as she cheered for Ash's training when it was past her bedtime and Clemont walked her to bed. I still just love how she's treated as being a kid her age in every conceivable way while still being adorable and fun.
The gym battle rematch was also well done overall. Lots of strategies and counterattacks done. I'm okay that it only lasted half the episode, while the first half was devoted to counter-training. Not every gym match needs to last an entire episode. I am, on one hand, a little disappointed that Fletchling didn't get a win, while Pikachu finished both of Viola's Pokémon - after all, Fletchling worked just a hard as Pikachu to prepare for the rematch - but no big deal.
Lol @ Clemont's invention actually helping Ash, both before and after it falls apart. XD