I've grudgingly and gradually come to realize that, in the long term, a person's life is a lot more like an aircraft carrier than speedboat.
This is perhaps why short-term motivation can't get the job done. To turn an aircraft carrier, you need miles of room out at sea, plenty of fuel, plenty of timing, and you need to coordinate with very many staff people on the ship and any pilots up in the air.
"I want to do better writing" -- this wish is almost always answered for me, but not promptly. It's like I've put in an order to an Amazon.com of Creativity and Achievement, but chose the slow free Super Saver Shipping.
Sure enough, a week or two later, my writing will start improving. Better ideas will come; perhaps my subconscious was working them for the entire 7-14 days, beginning very subtle movements and firing of engines and re-doing schedules so that the aircraft carrier can imperceptibly begin turning.
But I notice that, when I'm rapidly changing objectives and not seeing things through to completion, it's like I'm missing the deliveries as they come; I'm out-running my own resources; I'm running faster than things can be achieved.