The gum thief : a novel / Douglas Coupland.

Enhanced descriptions from Syndetics:

The first and only story of love and looming apocalypse set in the aisles of an office supply superstore.

In Douglas Coupland's ingenious new novel--sort of a Clerks meets Who's Afraid of Virginia Woolf --we meet Roger, a divorced, middle-aged "aisles associate" at Staples, condemned to restocking reams of 20-lb. bond paper for the rest of his life. And Roger's co-worker Bethany, in her early twenties and at the end of her Goth phase, who is looking at fifty more years of sorting the red pens from the blue in aisle 6.
One day, Bethany discovers Roger's notebook in the staff room. When she opens it up, she discovers that this old guy she's never considered as quite human is writing mock diary entries pretending to be her: and, spookily, he is getting her right.

These two retail workers then strike up an extraordinary epistolary relationship. Watch as their lives unfold alongside Roger's work-in-progress, the oddly titled Glove Pond , a Cheever-era novella gone horribly, horribly wrong. Through a complex layering of narratives, The Gum Thief reveals the comedy, loneliness, and strange comforts of contemporary life.
Coupland electrifies us on every page of this witty, wise, and unforgettable novel. Love, death and eternal friendship can all transpire where we least expect them ...and even after tragedy seems to have wiped your human slate clean, stories can slowly rebuild you.