I've told this story before but it bears repeating. Once upon a time a poor baker realized he couldn't go on and had to close his store because he had nothing left. As he and his wife were closing up for the night a poor beggar came along and asked for help. The baker and his wife took the poor soul in, shared what little food they had with him and gave him a warm place to sleep by the fire. In the morning the beggar thanked them as he left and said: "That which you do first you shall do all day." The baker and his wife opened the shop wondering what to do. They decided they would make cookies for a sick little girl down the street. They couldn't stop, and somehow they never ran out of ingredients. Customers came in, lured by the delicious aroma. They helped themselves and left the money on the counter since the baker and his wife were too busy making the cookies.. A grocer across the street looked at all this activity and the money flowing in. At the end of the day he asked the baker what had happened, and the baker explained that they had given a beggar supper and a bed for the night. The grocer hurried out to look for the beggar and invited him home for the night. He didn't do much - after all he was just a beggar - so he gave the poor fellow a crust of bread and some thin soup and a hard rug to sleep on. In the morning when the beggar left he said, "That which you do first you will do all day." The grocer and his wife hurried into their shop. "Quick," he said, "you sweep the floor and I'll count the money so we'll be ready for the customers." And that's what they did all day. They couldn't stop to serve anyone, so people left in disgust without buying anything.
I think of that all the time. Write first, do something else later. Be careful what you do.