While other people are being snatched away from us, we are being filched away surreptitiously from ourselves. –Seneca, Letters from a Stoic, Letter CIV

When Seneca wrote these words, he was trying to convince us that it was pointless to grieve for the loss of loved ones, because we are ourselves are being changed and worn down by the passage of time, the departed have merely suffered time’s final blow.

I think he has missed a deeper point, however, that the death of someone we loved, with whom we spent a great deal of time and shared many experiences represents a significant change and loss for us because of the oft overlooked collective and social nature of memory. When a friend or family member dies, a huge section of our memory is erased; we still have our memories of them, but we have lost their memories of us.

In…