EVERY YEAR on my birthday, from the time I turned 12, a white gardenia was delivered to my house in Bethesda, Md. No card or note came wiht it. Calls to the florist were always in vain -- it was a cash purchase. After a whole I stopped trying to discover the sender's identity and just delighted in the beauty and heady perfume of that one magical, perfect white flower nestled in soft pink tissue paper. But I never stopped imagining who the anonymous giver might be. Some of my happiest mom...