LIBRA (Sept. 23-Oct. 22): "The most important thing is to find out what the most important thing is," wrote Shunryu Suzuki in "Zen Mind, Beginner's Mind." That's your assignment for the next three weeks. Do whatever it takes to find out beyond a doubt what the most important thing is. Meditate naked an hour a day. Go on long walks in the wildest places you know. Convene intense conversations about yourself with folks who know you best. Create and sign a contract with yourself, vowing to identify the experience you want more than any other. No waffling. What's the single most important thing?