There are three things that cause us to act or make decisions. Thoughts. Feelings. Emotions.
Thoughts- these are of course what we know, what we believe.
Feelings- these are more like impressions, gut feelings. They are easily confused with emotions.
Emotions- these are different than thoughts or feelings because they are the body and mind's reactions to situations.
Though thoughts and feelings aren't always dependable, emotions are rarely so. They teach our minds to be creatures to be acted upon, not creatures to act. This is a concept that I have found hard to explain in words. I will try to give an example:
Let's say you are in a relationship with someone. You have a date planned for Friday night and they cancel. Your 'thoughts' are that they haven't done that before, there must be a good reason. Your 'feelings' are, trust them. It will be ok. Your 'emotions' are angry. They tell you they are standing you up. That they must not like you as much.
I believe an example of a different nature would be good to hear also:
You just met a guy/girl. Your 'thoughts' tell you they don't quite 'fit' the type of person you would be happy with.(based on passed experience) You can notice things about their personality that just isn't a 'match' with yours. Your feelings are just move on. Don't get too involved. But your 'emotions' are 'oh, but I really like him/her'. Maybe things will change. I don't want to stop or give up yet. They will more than always lead you astray. On the rare occasion, emotions are aligned with our thoughts or feelings. Rarely.
Thoughts and feelings lead us to correct conclusions. They teach us to trust ourselves and make conscious decisions.
Emotions teach us to react to situations and the decision is already made. Yes, the decisions that emotions make are based on our past thoughts and feelings. But the problem with that is that the current situation is never the same as a past one. It would be like taking a headache medicine because your stomach hurts. Sure it is pain, but a different kind, and hence must be treated differently.

a gift and a curse

So not sure if anyone has seen the TV show Monk. It is about a genius detective who has major OCD. It helps him solve cases but of course makes it hard for him to cope in society. He says it is 'a gift and a curse'.
I feel that way also about something. It seems that I have the ability to see a little deeper into things, a little past the obvious. In so doing, I see truth or 'non'-truths. It is great because it helps me realize what is right and what is wrong. But at the same time, it is depressing when no one around you sees those same things so clearly. Now when pointed out they see and understand. But not until then.
This may at first not seem like that big of a deal. But what if a friend, colleague, or worse, someone who you are in a relationship with, can not see these things. So they continuously do the wrong thing. Not only that, but they continuously don't see it. Now for most people this is ok. I believe most people are in a relationship with someone that is either as smart or as dumb as the other.(which ever way you want to look at it) That may sound like a bad thing, but it is good. That way the other person is on the same level. It is an equal relationship.
But let us be honest with ourselves. There are different levels of a relationship and definitely different types of people in those relationships. It isn't just if you are a good or bad boyfriend/girlfriend or husband/wife. There are many different degrees.
The problem is this: as your degree in a relationship increases, and this is measured by many things, common sense, self sacrifice, understanding, listening ability, etc., the number of people who match that degree decreases. It is what they call an indirect relationship. As one increases, the other decreases. So your chances of randomly running into someone who is at your level, or someone you can really relate to and be in an equal relationship with, drastically lessens.
So referring to my statement earlier, it is a gift and a curse.