Our lives disconnect and reconnect, we move on, and later we may again touch one another, again bounce away. This is the felt shape of a human life, neither simply linear nor wholly disjunctive nor endlessly bifurcating, but rather this bouncey-castle sequence of bumpings-into and tumblings-apart.
DNA is ROM. It can be read millions of times over, but only written to once - when it is first assembled the birth of the cell in which it resides.