The Coffin of Life

I'm trapped in a coffin
that is floating downstream,
along with countless others
who all have the same dream:
To break out of their box,
to encounter what they've not,
to swim for a while,
but that while isn't a lot.
The end would come quickly
if we were to break out,
but there's a waterfall anyway
at the end of our route.
Some crash into rocks
while other coffins slowly descend,
but the most break out
only when they're close to the end.
If we worked together,
we could build a boat
using each others' coffins
so we could stay afloat.
But we do not do this,
and because we don't,
I won't wait until the waterfall
to see the unknown.