Assertiveness is not what you do, it’s who you are! — Cal Le Mon
Don’t let people take advantage of you. The issue here is twofold. First, an unfortunate element of human nature is that letting people take advantage of you encourages them to repeat the behavior in the future. The more people take advantage of you, the more people will take advantage of you.
Second, being taken advantage of evokes anger, frustration, resentment, and related energy draining emotions and feelings. Along with being unpleasant, these emotions and feelings are unproductive and divert attention and energy from cognitive processes and especially from intuitive processes. The manifest cost of being taken advantage of is apparent but the hidden cost to one’s intuitive capacity is even more disabling. For you, the bill associated with letting people take advantage is quite simply too high.