The Aliens who abducted Arnie ALSO abducted Becky, and replaced her with an alien replacement
who used her/its mental powers to convince everyone that she was the same person even though she wasn't. After a couple years, it's mission was over and it was replaced with the real sister, Becky, again.
- And then came back, then went away, then came back again.
The Timing works, sorta. Maybe he unknowingly fathered a child with Samantha?
- Scrubs is what would have happened if the Conners were a wealthy upper-class family instead of lower/middle-class.
- Big Bang Theory is what happened if Mark/Davids mother had been more nurturing.
- Except for the fact that his parent in The Big Bang Theory was anything, but nurturing.
- Maybe David channeled his rage at Mrs. Healy's neglect into physics instead of the arts.
- Reba is what would happen if Roseanne and Dan got divorced.
David and Mark's father is different from the man their mother divorces in Season 5
A certain amount of Fridge Logic
suggests that David and Mark have a different father than the two younger siblings. In Season 5, when David tells Darlene he's running away, it's because his "parents" (it's not out of the realm of possibility for David to think of a step-dad as his "dad" if his mother re-married when he was very young) are getting a divorce. This is why the girls go to live with their father but David has to stay with his mother. It also explains
why she's so angry and abusive
toward him. She says "You're abandoning me, just like your father," then verbally abuses him in front of Roseanne. David reminds her of her low-life ex, which fuels her abusive personality. Even later, when Mark shows David how to tie his tie for the wedding and says their dad did nothing for them. But in David's earlier appearances, his "dad" (or possibly step-dad) is a buffer between David and his mother. He can't put up with her, either, which is why he leaves, but why would he abandon David to her if David were his biological son?