Poring over the Guardian's 1000 novels everyone must read list last week was one of those exercises that left many of us sighing, Marvell-like, "Had we but world enough and time …" The imperative in the series title created a thousand little trade-offs in the head: no, dammit, I still haven't read Vanity Fair, but I did get through Mark Z Danielewski's House of Leaves on a Barbados beach as I was about to turn 40.

It all evoked once again the unanswerable question so often put to readers: "Where on earth do you find the time?" The worry is that the answer might involve some kind of guilty confession. People who genuinely can't find the time to read are not necessarily unequal to the task; more likely they're bringing up children, working late, or cleaning the windows instead of lolling on the sofa turning pages.

Where did I find time to read Middlemarch last year, or the three Henry James novels a couple of years before? In truth, I'm really not sure. Most of us, I imagine, squeeze our reading into long train journeys, morning commutes or quiet lunch breaks when the noise of the office is tuned out for a precious hour of soup and Murakami. This is reading for those who can't do without it; the kind that outlives the days of student torpor, continues through lives crowded with incident and duty, and hardly ever feels like either a chore or a self-indulgence.

Will there come a time when reading really does seem like a prodigal waste of time? Despite the intellectual stimulus we might derive from even the literary equivalent of junk food, is there not a sense in which reading is the original couch potato non-activity? Might settling down for the afternoon with a new novel come to seem a lazy indulgence that should be forsaken in favour of a bracing walk along the seafront? Assuming clement weather, reasonable health and a few quid to buy yourself a coffee, isn't there something spiritually more nourishing about getting out into the world than taking the solipsist's line of least resistance and staying home with Edith Wharton?

No, I'm not talking myself into it either. Nor do I intend to take Edith along the prom, however much she might benefit from filling her lungs. But I do wonder whether a moment might arrive when the must-read impulse falters: when you accept that your life has not included The Death of Virgil, that there is neither world enough nor time, and that the once monstrous edifice of unread books was just a trick of the light. Until that time should come, though, I still have reading to do.