Just as we know what motivation means, "a reason or an act that makes someone acts the way they do" motivation can come in different ways, we can be motivated by what we hear or what we see or even what we feel, so allowing someone to demotivate you means not being sure of what you want because when someone is motivated the person definitely have the urge to actualize the dream in which he or she is being motivated for.
RE: Don't let others Demotivate You...!