Here's a quote from the posting:
In practice this means that, for example, when I am depressed I most easily remember episodes and information that I encountered during past periods of depression (by depression I mean a mood, not clinical depression). We've all experienced how our moods seem to feed themselves, but just think about it in terms of identity. Identity is essentially composed from a series of key memories about the experiences that we have had and what we have made them mean about the world. If I am building a definition of myself (to a certain degree) from my own memories, then my understanding of who I am when I am depressed is significantly different from who I think I am when I am happy or calm simply because I am constructing my identity from a different set of memories.
(In the spirit of full disclosure, this is my daughter Jordan's most recent posting.)