In preparation for an overseas trip, I’ve been packing up my books. As I take them from the shelves, I discover titles I’d long forgotten. The process is nostalgic. Books are like songs: they transport us instantly back in time. They can evoke images, thoughts, feelings gone but still residing somewhere within us.

I flick through The Wonderful Flight to the Mushroom Planet, see the sketchy pictures of the mad scientist, the cobbled-together spaceship, the mushroom planet, and still feel the excitement experienced by my childhood self.

Interestingly, the children’s books I find provide a fairly accurate picture of my current tastes: Rosemary Sutcliff, Alan Garner and too much Tolkien to be healthy. Stories of Vikings, stories set in the Roman Empire. Along with the science fiction, there is plenty of fantasy. A sprinkling of classics and fairytales (sometimes retold for children).

More than anything, childhood books evoke a wonder that only a tiny proportion of adult books can. But I’m careful not to re-read most of them. The adult eye is too critical. It refuses to enter the suspension of disbelief; plot-holes are too easily found; the sets are revealed as jury-rigged with cardboard.

Only later come the political books: Marxist classics, feminist and literary theory. But even here, recapitulations of earlier interests. The literary theory dissolves into criticism of speculative fiction. Much of the political history is about antiquity, such as Geoffrey de Ste Croix’s Class Struggle in the Ancient Greek World.

It seems that I have, over the years, remained mostly consistent: the growth a spreading of interest rather than a restructuring.

If books can evoke wonder and excitement, they can also bring less salutary emotions. I cannot pick up Thomas Mann’s The Magic Mountain without thinking of a particularly unhappy relationship break-up in my early twenties. A single flick through its pages and I’m straight back to that hot summer. The book was a present; I carried it in a bag with me to Sydney, the nectarines in my luggage staining some of its pages a slight orange. I read its opening pages as I realised with shock that the relationship was senselessly disintegrating around me. Days later, I had put The Magic Mountain aside, too unhappy to read.

I’ve never finished it

Other books take me back to political fights, to moments of illness, to people and places that are now gone forever.

Among them are plenty of unread texts. Many were presents. Some are collector’s items. Others I need to read for work.

I perform a terrifying calculation. If I read a book a week for the next forty years, I will have read roughly 2000 books. That’s if I read a book a week. Let’s say it’s a book a fortnight: that’s a thousand books. It doesn’t seem that many, really.

I’ve become prone to such calculations as I get older. It’s not really healthy. I don’t recommend it. (I know you’re performing them now, though. Best not.)

Books come to represent the slow whittling away of life’s possibilities, the way that the branches of our lives slowly contract, leaving us with fewer and fewer choices. As with closed-off career choices – I will never become a soccer star or a helicopter pilot or a surgeon – books become a measurement of the aging process.

The truth: I will never read all the books I would like to read.

Soon the packing will be complete and I’ll be flying off overseas. Each box is labelled and so becomes a kind of time capsule, a small container of my history. I’ll feel that a part of me has been left behind. There was a time in my early twenties when all I possessed was a suitcase of clothes and a few boxes of books. If you’d asked me to choose between them, I would have chosen the latter.

In the future, fewer people will be able to pack up their libraries. Rather, they’ll place their electronic devices into their soft cases. Can a reading device retain the same anchoring of sentiment? Will the new readers be better off?

But I haven’t made that transition. Each of us is anchored in our historical time, in a way not so different from the way content is anchored to the physical forms of books themselves.

Whatever the case, a new phase of life means acquiring new books. New interests, new authors, new people met and places visited. The future – even if its possibilities are constantly diminishing – is still open. Where there’s life, there are books.