It happened again today.
It happens most often when I'm driving by myself.
It could be that my mind is more free to wander when I'm driving, just watching the road, not thinking about anything in particular.
When it happens it's like a dark cloud passing over the sun, followed by a shaft of piercing lightening, a rumble like thunder in the depths of my soul and the pricking of precipitation behind my eye lids.
It almost always follows an innocuous thought.
An inane contemplation.
Always it comes unexpectedly, washing over me with a shock like a cold wave.
He's just gone.
And the sadness, like a fog, rolls in, obscuring the vision for awhile.