Imagine driving a car that isn’t working well. When you step on the gas the car sometimes lurches forward and sometimes doesn’t respond. When you blow the horn it sounds blaring. The brakes sometimes slow the car, but not always. The blinkers work occasionally, the steering is erratic, and the speedometer is inaccurate. You are engaged in a constant struggle to keep the car on the road, and it is difficult to concentrate on anything else.