Other responses have articulated it a lot better than me, but I still want to say that I think you have misunderstood what many ‘gurus’ mean when they say “living in the present moment”. I think that what we now call “living in the present moment” is the collection of practices taken mainly from Eastern philosophies that are thousands of years old, and thus have hundreds of interpretations, methods and reasonings behind it, some of which might not be so enlightened, however, the way I’ve come to understand it, it’s not about giving in to whatever impulse runs within you at any given time like you put it, but rather, trying to experience reality, this moment, as it is, without labeling it with thoughts, judging it good or bad, simply being. I think you don’t have to enter a deep meditative state to enjoy the present moment, children usually are like this when they are playing. I think it’s also about finding happiness with what you have, not as a way settling with something less that you deserve or desire, but as a way being thankful with the blessings you have. Anyway, there are many considerations, but I think it’s a practice that could certainly help us be more mindful in our daily lives. Its been proven practices like meditation, which many essentially describe as a “living in the moment” practice, improves concentration, and increases will power, which actually help us control impulses, and has an overall positive effect in our body and mind.