A friend called the other day.'How are you?' she said.The sun was shining, the sky a merciless blue. It was only eleven in the morning but I had been awake since three twenty. I was in bed because, as usual, I could think of nowhere else to go. I said that I was feeling low. Low is the depressive's euphemism for despair.She said: 'How can you be depressed on a day like this?'I wanted to say: 'If I had flu, would you ask me how I could be sick on a day like this?