That impromptu trip to the mall that lasted a couple of hours? That’s 1 percent of an intimate relationship logged. The cookout in your backyard that spans an entire summer’s afternoon? You’ve just racked up 3 percent of a ride-or-die friendship. The constant togetherness at the two-day women’s retreat? That’s a good 25 percent right there. My guess is that the reason you feel close to certain people is that you have faithfully put in the time together.