Is love enough?

When in a relationship, how does one gauge when it is enough? What will it take to fill up that void inside? Is it trust, laughter, time spent together, mutual understanding, or sex maybe... Some may say all of those qualities rolled up together is necessary. But what happens when a few of them are missing?

Is dating very much like taking a driver's license test? You are riding in the passenger seat judging the prospective driver all the while holding your clipboard and going through the list. By the end of the ride, all is left unchecked except for that box placed to the left of "love". 

When is love, alone, enough?