When you're getting involved with someone new, you should rely on your close, trusted friends for their opinions of your potential sweetie. The problem is, you're just not the greatest at choosing a mate for yourself, because your perceptions are muddled by love. When you fall for someone, your admiration for them just cancels out everything else.
You ignore red flags and are blind to their faults; all you can see is how wonderful they are, how goofy in love they make you feel, how the whole world is full of sweet music and roses! Of course, on the one hand, that can be a positive thing; you certainly do bring a sense of reverence to a love affair that can really deepen the emotional experience for both of you. But you have to make sure that you're in love with the person you think you're in love with. They could take advantage of you and you'd never know it, because you blind yourself to reality, preferring to live in a fantasy world where love conquers all. You idealize your lovers and your relationships, which can be crushing when you're finally forced to accept that the relationship isn't going to work. Try to avoid this disillusionment by choosing well in the first place, attending to your small inner voice when it complains, and asking your friends for guidance.