A bagel with lox is about the happiest food there is for any New Yorker worth his or her imported gray sea salt. For many, especially in neighborhoods with longstanding old-school appetizing stores, it's not quite a Sunday morning (-ish time of afternoon) until they've had their bagel, thickly shmeared and boasting an generous inch-thick layering of hand-cut, house-smoked salmon. Garnishes may or may not include a full slice of red onion — no rings here — tomato, lettuce, capers and a lemon wedge. A few twists of cracked pepper is excellent. This is not a fancy thing. It's just a very, very good thing. Have a nice Sunday brunch on a random Tuesday lunch break. It's not verboten.
While everyone may not have access to the magical fishwares of Russ & Daughters or Barney Greengrass, bagels and lox are all over the place. Vacuum-sealed packs of pre-sliced smoked salmon of above-decent quality are available in most supermarkets, as are, believe it or not, both bagels and cream cheese. I like the whipped variety for bagels because it's a little lighter, spreads really easily and mellows out the saltiness of the salmon without taking over. Try making your own gravlax at home; it's like lox but with a grassy, herbal dill flavor instead of smoke.
You reach for the sliced turkey because that's what you've been programmed to do. Make yourself a classy little bagel for lunch.