Wow. I really enjoyed last night's episode, even though the end was one of the most painful moments we've had on the show in 5 seasons. I love seeing Ash again and learning lots of tidbits about the boys childhoods. Their memories were great, but also bittersweet. I think my favorite scene would have to be Dean's memory of the 4th of July. I adore Colin Ford and any time we get to see little Sammy is awesome.
I did have a question though. Maybe someone has already done meta on this, but it's been bothering me. Why didn't we see any of Ash's memories? Ash and Pamela never mentioned reliving any memories, they just talked about their heavens. Ash's heaven is the Roadhouse, and Pamela's heaven is a huge rock concert. Is Sam and Dean's heaven driving in the impala? Will they get to enjoy that once they've relived all their memories? Maybe I just missed the explanation in the episode, but the whole memories thing kind of confuses me.
Furthermore, how much was Zachariah interfering in their memories? I've seen several people that were angry with Sam because none of his memories that we saw included Dean. My sister and I were talking about it, and my personal canon is that Zach started messing with them after they left Sam's memory of Flagstaff with Bones. After Dean finds Sam, the next two memories they transition to because one of the boys see something from their childhood (toy racetrack and a postcard). When Dean walks out of the house in Flagstaff, all of a sudden they're in Sam's memory of the night he left for Stanford, and we're supposed to assume its a happy memory. Maybe it was, partly, but that had to have been hard for Sam to leave his family. But there was no transition like the last two memories. Maybe this isn't what the writers were going for, but I'm going to assume that Zachariah started programing their memories not only to find them more easily, but to mess with their heads.