Yes Kimmerz, notice how they "find" that passion to pursue what they think they want. What they don't seem to realize (the depression coaxing them) is that the passion is coming from within them. They think the passion is coming after the fact, as a result of this new change, new love, new apartment / job / car.
That chemical released in the brain is doing the same thing for them as the alcohol or other drug is doing. Allowing them to avoid the depression. The booze gives them passion and fills the void, or the OP does...
Depression seeks to avoid by reaching out for external stimuli.
The whole "I can't go back there" is them thinking that a metaphor is reality. "There" being their fear of the void of depression. But they relate it to being literally us, or the M, or our old house, or whatever... "There" changes as they loose their current passion for something / someone and the run to the next.
And the depression blocks their ability to see what was, before depression struck. It's a moment in time which is all the history they can focus on. And all their history begins to be re-woven around that specific moment.
My W also lashed out at me with words suggesting I had abandoned her and my Ds. All the while telling me and other common friends that she was the one who made the decision to exit the M. From what I can gather, her family and really close, unique to her, friends have one story (me being the bad one and leaving her or not being the H she deserved). That's the one I think they really believe. That their depression allows them to have, that they are the victim.
The other story, which they might tell mutual friends and the spouse and similar people (people that they have not enlisted to support them), is one where they left the M as it was not working for them. Being the martyr. Because depression tells them they must atone. For depression tells them they are not good nor worthy.