I have time, for now, to address this observation.
I think that it's not possible to know one's self, without knowing also one's other. Not one's friends, family, significant others et al, but, one's own other. Say, the part that says God doesn't exist; along with the part that says God does exist.
Only in this sense can one truly live only once. To be on the right path, so that one is definitively where one is, instead of scattered, however, throughout the ages.
P.S. Noticed, this afternoon, that the days are becoming longer, again. I guess that the time it takes to do so, after December 21/22, reflects one's day-to-day power of observation.