Rembrandt's self-portraits span his timeline from youth through to old age.
They are marked by an absence of vanity about his appearance.
The artist's face is unremarkable.
Its features are blurred by a layer of pudgy flesh.
The bone structure lacks any sharpness to catch the light and lend drama to the homely face of this man who painted human emotion into each brush stroke he laid onto canvas.
Nearly thirty years ago, I was visiting the Prado in Madrid at a time when one of Rembrandt's many self-portraits was on loan to the museum.
Knowing that most of the paintings I longed to see belonged to the State collection in Amsterdam, I was unprepared for such a delight.
To this day, my memory shimmers with details of how it felt to glance through an archway and see that portrait.
The museum posted multi-lingual signs warning visitors of the prohibition against touching any of the artworks on display.

• Security guards armed with pistols patrolled the rooms to back up the notices.
  Yet I could not resist.
  

Staring straight ahead, scrubbing my pinky with a facial tissue to remove any body acids, I walked towards that canvas worked on by the hands of Rembrandt - the painter I most admired.
Onto a plain section of background, I pressed a reverent fingertip.
Then, tears spurted from my eyes and drenched my cheeks.

• Two uniformed guards, who had been closing in on me, backed away.
  They realised this particular fool was not one who posed any danger.
  

Little wonder I was so deeply moved by that portrait.
All these years later, though, I think I might have responded in the same way to any work by my painting 'hero,' seen in reality for the first - and perhaps the only time - in my life.
Self-portraits, like autobiographies, hold little interest for me.
When you think about it, the only autobiography which could be truly honest is the one with an embargo on publication until fifty years after the author's death.

• Only under this condition could the whole truth of a person's life be revealed.
  Even so, human decency - in consideration of family, friends and lovers - and human vanity on the author's part, make me doubt any such document can exist.
  It would be of interest to a publisher only if the author had gained huge celebrity during life.
  Few artists can know, at the start of a career, that their work will achieve the kind of value that survives their maker's death.
  

• An artist who makes self-portraits over an entire life-time is creating - whether deliberately or not - an autobiography in paint.
  

Sculptures and well-crafted paintings can be maintained in good condition for thousands of years.
So, I wonder: is it unbridled hubris that drives artists to make 'immortal' images of themselves? Is it an irresistible curiosity about the development of their personality, as displayed by their facial expressions? Might it be fascination with how life's experiences and the inevitable process of ageing change the familiar image in the mirror?

• Some wag once remarked that in the case of Rembrandt, simple poverty may have given him little choice but to employ himself as a model.
  No credence can be given to this fancy, for at least two reasons:

1.
Rembrandt's long period of popularity with wealthy clients and his studio of paying students and apprentices.
Only late in life did he fall into a state of economic hardship.
2.
Rembrandt is just one amongst a legion of artists who, through the whole of history and in all regions of Earth, have made self-portraits.
Some, like Van Gogh, have written copiously in diaries and personal letters about their motivations to make the art they did.

• We can only speculate on Rembrandt's motivation, because he left no clue in his papers.
  The only writings in Rembrandt's hand that remain in existence are a few letters to clients and receipts for fees.