For Pokemon X and Y, I got stuck in Lumiose City. I couldn't figure out what way I was supposed to go and every road I turned, there was some construction worker dude that stopped me, told me I couldn't go down there, and I was like "okay, where can I go, then?" I know I needed to do something to advance the storyline but I think I forgot what it was and never picked it back up again to figure it out.

For Sun and Moon, I think the second island trial was the deathblow. It was a Nuzlocke run and that darn Wishiwashi just up and MURDERED all the Pokemon I was hoping to raise into powerhouses, leaving me with like three remaining that I just didn't care for and the thought "do I have to work with these guys?" And the thought of "hey, you've got WAY more of these island trials coming up and now you've got barely a team left to work with! Bet you're ready for more of this fun!" No. Some other game came along (probably Overwatch) and easily snagged my interest out of playing Sun any further.

I know, both those cases were super-early plug-pulls and I'm not exactly proud of either of them. I'm not planning on Nuzlocking Sword/Shield. It worked great for Black and was a fun approach, but after what happened with Y and Sun, maybe it's time to put that play approach on the shelf this time and go back to the regular "what I want to work with" team that will probably make the game more enjoyable.