In the last season finale, Dean returned to Lisa and Ben in an attempt to settle down.
"He feels as though he's got an opportunity to live a normal life," Ackles told DS at Comic-Con. "It's something that he's always dreamt about."
Ackles explained that Dean will be "living that life" when the show picks up a year later but revealed that he will not be able to give up his old habits.
"He's still got the shotgun underneath the bed, still carries a pistol in the truck," Ackles said. "The Impala's underneath the tarp in the garage. So it's a bit of a big shift for him. But of course, inevitably, he starts to get sucked back in. And he can't fight his past. It starts catching up with him."
Supernatural returns for a new season on September 24 on The CW.
> Click here to watch our interview with Jensen Ackles