There are two interpretations as to why we are susceptible to this. First is the obvious one – there is some latent desire within, in “seed-form”, and this seed is “watered” by external influences and made to grow. The second interpretation is that this world creates its own problems, and by the necessity of being incarnated here, we are “persuasible” – we keep trying to find solutions to extant and obvious problems, such as food, shelter, transport, protection from harm etc., and I think this is the correct interpretation for your example. It’s not that you have a latent desire for owning a house, that would survive the death of your physical body and cause rebirth, as those things are explained in classical literature; you just have a realistic issue at this point of your incarnate existence, and you can be “persuaded” by the world-based forces to try to find workable solutions to the problem while you are here. It’s in the same order as knowing you’ll have to eat in the future so you need to plan ahead and buy groceries to make lunch.
I think the most important thing about it is to be constantly aware and vigilant. We need to do things while here, yes, but there is a difference between doing and overdoing, which is something I’ve been made aware of recently. 🙂 Also, we need to be able to let go instantly when the duties and services we perform here are no longer required, and that’s basically not always easy; when I test myself for this, by creating a hypothetical scenario of having to leave this world today, it’s not attachment to things that would bother me in the slightest, it’s the duty and responsibility to people. How would they pay the bills, how would they manage logistics, did I leave them with sufficient knowledge and abilities to make due without me? Am I leaving them in a death-trap, or in a workable situation? If I am told from above that it’s my time to go, so it’s not a matter of choice, would I still feel bound by responsibility?
It’s not an easy thing to quit “cold turkey” something you’ve been doing for the better part of your life, and this, I think, is the problem with attachment. Not the silly things the scriptures warn us about, the stereotypical nonsense about people worrying about their business, money, property and so on. It’s the real issues that are the problem, not the obviously illusory ones; and if there’s anything real here, it’s the souls that are incarnate, especially if it’s your specific duty to care for them, and it’s not easy to just stop doing that when you’re told it’s no longer up to you, because your time here is up. I’m not sure I have the right answers here, at least not the universally applicable ones, because the entire situation might feel like a non-issue from a different standpoint that includes a wider perspective, such as viewing the totality of karmic intersections and branches of all involved, and understanding that there are no good solutions and stable states in this world; it’s by definition a quagmire of quicksand and landmines and not a place to build your lasting home, and that is as true for me as it is for everybody else, so if I am completely accepting this fact about my own life, why am I still insistent on trying to fix everybody else’s situation, as if that were possible here? It’s obviously something I’m struggling with, the over-exertion of responsibility for others into the realm of unhealthy, where by “unhealthy” I mean behaviour that doesn’t accept that things are inherently unfixable here, and no amount of investment of effort will change the fundamentals.
I think the real answer would be that the struggle against the nature of the world is the right approach while we are here, because that’s the only way to maintain your spiritual sanity and have a working soul-presence in the world; however, it needs to be understood that it’s not a battle against the world, but the battle for presence of God in one’s life, and once you’re out, you’re out, and we need to preserve sufficient awareness as to cut all energy investments and expenditures instantly, when it is no longer required for the actual goal, not the fictitious ones that constantly spawn in this mirage of a place.

Oh, I’m certainly not above such things myself; I would just have to be in a realistic position where I actually needed a new car. 🙂 But barring that, I can be persuaded to pursue desires by proxy, and since those have the false legitimacy of being “selfless”, they are easier to fall for. Sure, there’s a core of legitimate responsibility in getting your kid a car, but what I ended up buying him is shooting past this legitimate core and into the realm of wild overachievement by a huge margin; I got him a fancier car than I’m driving. 🙂

I don’t know about that; it might actually be more of a problem, because it’s masked by virtue and therefore reduces your ability to control it. That’s what women usually tend to fall for; they project their desires into their children, and since that is falsely perceived as “altruistic” by the society, they get so wildly crazy about it, that it is possible for them to completely lose their spiritual detachment and identity in it. Basically, how is women projecting desires into their reproductive vector any different from men trying to inseminate as many women as possible, which is perceived by society as sinful? I don’t see a real difference; both are pure biology, animal behaviour, but one of the two managed to successfully cloak itself in the appearance of virtue.

You absolutely feel everything because, once you absorbed the additional karmic mass, it *is* you. It became integrated into your soul-core and you feel all the emotions, trauma, stress, pain, attachment and other wildly energetic emotions that came with it; that’s the “increase in temperature” I so abstractly talked about, but it doesn’t feel abstract, and the “kinetic energy of the particles” feels like spiritual whirlpools, savagely violent; sin and justification for it, and when sufficiently detached, remorse and pain, violent pain you live through, and it’s no longer someone else’s, it’s yours because you integrated it within yourself. You need to “learn” the lessons again, because in this new state you “forget”, because you’re at the “higher temperature” now, and none of it feels like somebody else’s problem, because you are swallowed whole, and it often takes some time before you even understand what’s going on, why you are feeling all those things and why you are disturbed and in pain, or full of desires pointing in strange directions, and when you understand what’s going on, it means you achieved the first degree of control, that you attained detachment sufficient to understand that it’s energy vectors and not “yourself”, and as you increase in detachment and re-acquire the ability to observe the process with detachment and let the wild emotions unwind without you whipping them back up, you gradually remove “heat” from your system, which is the “secret” of vipassana, of just observing the emotions and thoughts and fears/desires, which divests energy from them and creates the conditions necessary for the gradual cooling of the system, and this process of cooling can be called either “suffering” or “remorse”; it feels like both, with a slight difference that makes “remorse” a better word, because it implies detachment; you can “suffer” while holding on to the “sinful” structure, and the pain of suffering can be selfish and arrogant, but “remorse” means the distinction of letting go.