I'd say it's like a tiny smoldering piece of charcoal, that suddenly ignites when there's too much gasoline in the air. You may be aware of the signs early, and

I'd say it's like a tiny smoldering piece of charcoal, that suddenly ignites when there's too much gasoline in the air. You may be aware of the signs early, and even know what your progression is, but just before the tipping point you may still be a completely productive worker.