Rembrandt. Here’s the artist aged 59, a later example of almost 100 self-portraits. Look at the detail: the bulbous nose, the slight moustache, the subtle chagrin around his mouth, the wispy whiting hair. But mostly look – really look – at the eyes: the darkest thing on the canvas, portals of memory and of experience. We’re gazing into the past, his expression enigmatic and unflinching, but we are also, here and now, the object of his gaze, scrutinised. He is many things: monumental, defiant, humble, full of melancholy; most of all he’s almost shockingly real, his eyes the intriguing windows on an unknowable soul. The fortune we have in being able to trace the artist’s life through self-portraits is hard to overstate: we see him learn from errors of youth (“ever failed? Try again. Fail again. Fail better”) and, far from an exercise in vanity, these pictures become an extended dialogue between him and us – then and now – about ageing, about how we see, about memory, time, and most of all empathy: the absolute nuts and bolts of human existence.