When Warming Is A Good Thing.

Diane Ackerman's book An Alchemy of Mind:

"We safely trade bits of self with loved ones all the time. Couples pick up some of each other's mannerisms, accents, habits, ideas. But we also absorb people in more visceral ways. When we pass along a flu or cold sore, for instance, viruses pack some of our proteins and lipids in the viral envelope and release them inside another person, who will store some in his or her lymph nodes. Retroviruses - such as AIDS, for instance - can install pieces of someone else's DNA in one's chromosomes. But we're probably swapping gene fragments with people all the time, imperceptibly, through infection and lovemaking because 'over the course of an intimate relationship, we collect a lot of pieces of someone else... Until one day what remains is truly and thoroughly a mosaic, a chimera - part man, part woman, part someone, part someone else.' Little by little, as bits of DNA make it to our chromosomes, intimate relationships help shape the immune system's cameo of us, and modify the brain, altering the self whose continuity we cherish. We don't just get under each other's skin, we absorb people. Everyone we've ever loved remains with us, and we're invisibly changed for having known them. That will make some people feel queasy, I suppose, but it warms me."

<sigh>