Living for greater whole of society yet not thinking about own mortality looks like moving in wrong direction for me. They are not contrary lifestyles. The only problem with highest priority we all having right now as a humanity is very short lifespan and mortality.
I do not see much difference in dying in the next 12 month or next 40 years.
As a parent who's been the primary caregiver for my young kids for years, it pains me to die when they aren't able to look after themselves yet. It is my one regret, really. So another 20 years would be cool from that perspective.
There's also the difficulty in forming any real plans, which often take a few years, if you don't have some belief that you'll live to see them through.
So telling ourselves "I'm going to live forever" (or at least 20 years more) is a basis for making long term plans like buying a house, having children, planting a garden...
But when we are living in the thick of it we live much more within each other and the greater whole of society because we have to. That's how we survive. We give up some of our brainspace to ideas and systems that are built communally, both on a local/familial level and on an entire social level.
In other words, we spend a lot of our time going with the flow and allowing our opinions to be shaped by those we trust or love. Or at least I think that's part of it.
Edit: And in that sense we see individuals dying, but as we live we don't necessarily ponder ourselves dying as an individual because much of what we do and care about on a day to day basis will outlive us e.g. our families and ideals.