Lack of motivation means you aren't committed to keeping yourself motivated. If you were 100% committed to living with high motivation, you'd do it, starting with cutting all the crappy connections from your life that demotivate or bore you. As part of this commitment, you'd go out of your way to be around highly motivated people and to have them as regular presences in your social circle.
Motivation is very difficult to create unless you're going to commit yourself to it fully and completely. This typically happens when people finally get so fed up and disgusted with the unmotivated, lazy life and get clear that it's leading them nowhere and that they have to start doing the opposite.