On the one hand, I continue my month-to-month existence, with a small cash reserve put away on the side.  With the remainder, I enjoy going out to eat, drink, and take fairly modest vacations once or twice a year.  This is hardly an ideal situation, but it's no worse than that of my many, many friends who have enormous student debts hanging over their heads.  

On the other hand, I guard my rather meager income much more carefully, don't eat out or travel much at all, and save up enough money to think about things like investments.

If civilization continues in a recognizable situation, and present investments are not wiped out in a financial calamity, then I would definitely be a bit richer following the second course.  Yay.

If civilization continues, but most financial assets are wiped out, than I'm more or less the same either way, except I'd perhaps be a bit less bitter if I'd spent the money myself, instead of seeing it all disappear into inflation/asset value collapse/confiscation/etc.

If global warming/peak oil/financial collapse push civilization into a long, slow decline over the next twenty or thirty years, than I'll probably not die immediately.  More likely is several marginal years of homelessness and unemployment before I die of cancer or tuberculeprosy or something.  While savings might help mitigate my misery in such a situation, I have to wonder how well pre-crisis assets are going to hold up in value, and thus be useful.  Cash might be the best thing there is, or it might become totally worthless as governments turn to hyper-inflation to deal with unsustainable debts.

If civilization doesn't continue in a recognizable fashion, then I'll die, sooner rather than later.  I have no illusions regarding that.  So, savings are a bit of a moot point, whether they have value or not.