You never know art better than that which you’re forced to study as a teenager. For my O-level in music I had no choice but to listen in some detail to Malcolm Arnold’s Four Scottish Dances, Beethoven’s Pathétique piano sonata and Fauré’s Requiem. For a lad obsessed with the likes of Led Zeppelin, at the time this represented a traumatic listening experience. But it taught me a valuable lesson: if you’re exposed to any piece of art long enough, eventually it will move you. No pain, no gain, possibly. I’ve loved all three pieces ever since. OK, I failed the O-level, but I can hardly see it as a failure given it opened up a whole genre of music I might have missed. The Requiem has been particularly important to me. I listen to it driving home from the football whenever my team have lost. I listen to it often.

As far as literature is concerned, Thomas Hardy’s The Mayor of Casterbridge was a different kettle of fish. I loved it from page one. The first three paragraphs alone still make me want to applaud with my hands above my head, like I do when my team take to the field. Exactly 40 years since my O-level English literature exam (passed, with a grade A, since you ask), I decided to re-read it. Some passages feel as familiar as my name and address, while others – concerning the plot, mainly – ring no bells at all. Weird.

I loved it all over again, although one aspect nagged away throughout: the absence of any explanation as to why characters are as they are. Take Michael Henchard, who is angry, selfish and cruel, but also capable of great kindness and, tormented by guilt and remorse, isn’t lacking in the self-awareness department. I find that my 21st-century self asks questions my 20th-century self didn’t – answers to which the 19th-century author apparently felt no obligation to supply. Why is Henchard this way? What made him so mad and bad most of the time? What made Donald Farfrae so clever and kind?

Today, sure as anything, a writer would be bound to offer some kind of explanation. Not to do so might be deemed lazy – a cop out. If no origin story is supplied, the character might even be regarded as one-dimensional. Hence, we see the likes of Tony Soprano (bad guy) and Ted Lasso (good guy) in therapy, laying out their origin stories in some detail. Poor Michael Henchard never got this opportunity. His behaviour would be pathologised to hell and back. It must have been nice for Hardy to be able to devote his literary energies to creating complex characters without getting bogged down in backstories.

There’s a TV series in here somewhere: Great Characters in Fiction – in Therapy. Season one to feature Michael Henchard, Iago, Becky Sharp, Anna Karenina and all of the Famous Five, including Timmy the dog.

Now, in real life and on the page, we are almost impelled to investigate why we are like we are, and why everyone else is like they are. Done something terrible? There must be a reason that goes back a long way. These lines of inquiry probably come from a good place and are generally healthy, but there needs to be a line somewhere. People are often just plain good, plain bad or plain indifferent, in varying degrees of complexity. Just let them be.

If you’ve got the funds, you can spend a lifetime in therapy looking backwards in an effort to find a way forward. This has its place, but if we’re not careful we’ll be mulling over our pasts to make sense of our futures until the very moment the future stops dead as we’re lowered into our graves.

Sorry to end on such a grim note there. Been reading too much Hardy.

• Adrian Chiles is a writer, broadcaster and Guardian columnist