--Harrison waking him up in the middle of the night( Day 99 loser game )--Harry telling him to smile for a family photograph because that's what people do ( Day 114, Game 77 )---Pizza night with Rita and the kids( Day 115, Game 78 )With that in mind, current state of the Dexter:
These memories combined with his team actually worrying about him in the caves are combining to make Dexter realise that he
can be part of a team, and he should be. The last memory in particular felt pretty good, so he thinks there might be something to this fitting in thing even aside from Harry telling him he should do it. But even if he's not sure what the point of it is just yet, both Harry and himself told him to do it and he trusts his judgement, and apparently him-with-memories trusts Harry's judgement. Of course, he still doesn't really know how to go about it, and the team he's trying to fit in with is Cepheus so even if he
did remember all of Harry's advice it probably wouldn't help since team bros and psychos isn't exactly normal society. All he knows is that smiling is apparently part of it, and stuff from Claude's conversation with him about trusting teammates.
He still doesn't feel any particular attachment to anyone on his team, but he'll be paying more attention to how the rest of the team behaves and trying to imitate it to fit in better. He hasn't really made the connection that he's the "father" of the family with Rita, just that they're his family as an adult and he's closer to Rita than he is to the kids.
Also, he knows that his full first name is Dexter now, but since Harry also calls him Dex and it's clearly a valid name for him he's not correcting people when they call him that. He'll introduce himself as Dexter from now on though.
He's also started being more secretive about what his memories contain. He doesn't have any particularly well thought out reason for it, it's just that he sees them as private and he wants all the privacy he can muster in this place. He'll give enough information to satisfy his teammate's curiosity a little, and anything that would actually be useful to them in sabra, but he'll try and keep the details to himself as much as possible.
I feel like there's more I wanted to say but I can't think of it now so that's it for now \o/ If you have any questions lemme know.