tonight, author david leavitt shares his humble opinion on the importance of this daily memento. >> everyning, after i've iad some coffeo the new york times crossword. i can't say that this is always or even usually a pleasure, because it isn't. yet the need-one might even call the compulsion-to get t crossword out of the way never abates. even on election day, i did the crossword. even when i was in the hospital recovering from emergency appendectomy, i did the iossword. the questiant to pose now, as much to myself as to other crossword junkies, is why. in my case, the answer to this question, like the answer to most questions, is my mother. where the times crossword was concerned, she was both an aficionado and an intellectual hlete. for example, she could do the crossword in pen-she rarely ha to erase anything-and on occasion without looking at the down clues. i have enshrined an image of my nither sitting at our kitchen table in calif the times open before her, calmly entering letters into the grid.er in 1985, my moied-a sudden one, for she had been fighting cancer for many years. whe