Life imitates art - but how does that help?

Met an interesting actor at dinner on Friday. Experienced actor, lots of Shakespeare, thoughtful gent. So I asked a question, and the question was this: actors necessarily spend much time working out how to inhabit pretty extreme emotional states, and dealing with life's most intimidating problems (death, grief, violent rage). So, does that experience of any help when they subsequently face such situations in their own lives.

The actor didn't have to think about this for very long. He finished his mackerel and described going on stage in The Comedy of Errors immediately after hearing about the death of a young woman he'd met not long beforehand. He thought about the death of his father. And no, he said decisively, having performed situations close to these was of no help at all in dealing with their real-life equivalents.

But, naive question though it is, I have to ask: why? It's perhaps a tempting imaginative leap to a non-practitioner. From the earliest, unreliable actor biographies in the 17th century, people have been conflating performers and the roles they play. Pickering & Chatto has just begun what promises to be a rich and exhaustive series of contemporary accounts of great Shakespearean actors, from the mid-18th century into the early 20th. Looking at the first volume, it is clear that the public personae of resourceful David Garrick and racy Peg Woffington were shaped by the roles in which they specialised.

Equally, a modern autobiography like Beside Myself by the troubled virtuoso Antony Sher makes it clear that, for him, the process of exploring a dramatic character in rehearsal is not unrelated to the process of exploring himself in therapy. Macbeth's ambition, Leontes' jealousy, Richard III defiant rejection of family are all mirrored - though in vastly different degrees - in Sher's own psyche.

But none of that is quite what I'm wondering about. Yes, you draw on your own experience and emotion to create a character. But can you then draw on the characters you've played to sustain you at the most testing periods of your life? And, if not, why not? Does none of the searing intensity of performance map onto subsequent experience? Anyone with a view, let me know.