In the Decon AU Bill spends millions of years in the Theraprism and the road to recovery is long and angsty. But when he gets out... It's 2015.
It's only been three years since Weirdmaggedon.
He had made peace with the fact that he outlived almost everything he did. He could never apologize to the people he hurt (Part of him had been relieved at that, but more of him had felt sick)
He had tried to accept that he would never see Ford again.
But then he wanders through the woods, and crashes down a hill, and two kids (teenagers, now) who he tried to murder so-long-ago-not-so-long-ago find him... they're rightfully suspicious but he doesn't think they can't stomach taking a (seemingly) human life the way that their grunkles can.
He's speechless. He's frozen. He's still wearing an orange prison jumpsuit and he's pale as a ghost.
These are the kids he tried to kill. The kids he almost did kill.
...When did they get so tiny?
The thing about Bill and the twins is that he understands intellectually that they're children but not emotionally.
He hasn't been a child in such a long time or interacted with one in a meaningful way really really ever. In his head they're just tiny beings who are usually easier to manipulate. In abstract he understands that they're more vulnerable and more malleable, but in practice?
He never thought he'd understand it in practice.
He's spent such a long time seething over the twins and then sees them older and stronger and they're still so small?
He wants to puke.
It's the first time he apologizes to a member of the Pines family.
And then Mabel shoots him with a crossbow.