Why is my best friend so stupid?

You can’t.

There may be reasons for her pathological lying that go way beyond “impressing” anyone, they could be caused by current/past problems in her life that you really might not want to dig into that makes her create a false reality for herself.

Someone who lies that compulsively should probably get some help.

Yep, @sinscriven has it nailed. You can’t change her, you can only change yourself.

Start with not beating around the bush and be clear and direct with her.

Tell her you are on to her lies and that if she doesn’t stop you will not be able to continue in the friendship.

Make your mission statement and tell her what the consequences will be, ( loss of your friendship ) and then, STICK TO IT or, you lose all credibility as being a person that keeps their word!

I agree with @sinscriven and @Coloma. My wife had a close friend like this in high school, and beating around the bush never helped. Your friend needs professional help—and your support if you’re still willing to give it.

You need to sit her down, at a time and place where both of you can be calm and say something like this, “Angela, you and I have been friends for a long time and I love you like a sister, but sometimes you exaggerate things and tell out-right lies.” (at which time she will probably protest and you need to have at least 2 good examples to “remind” her of what she said, and why they are exaggerations or lies) then continue to say, “I would really like to remain friends with you, but it’s making me more and more un-comfortable to listen to you exaggerate and make up things. And it’s gotten in the way of my friendships and relationships with other people.” (provide another specific example or 2 right here) then continue with, “I wish you would just be yourself, or at least explain to me why you need to lie and exaggerate.” Hopefully she’ll explain why right here, but if she doesn’t or yells at you that she doesn’t do it, then continue with, “Like I said, I want to continue to be friends with you, but if you don’t stop doing this, I’m going to have to limit my time with you or even think about simply moving on. Do you want to talk about this?”

This may be a very difficult conversation to have, but I think it’s the only way to get to the bottom of why she does this, or to figure out that she isn’t going to admit it, and in that case, you probably have to move on from your friendship with this girl.

I suspect that she is probably desperate for love and friendship (and a boyfriend of her own) and she thinks that by making up stuff, that she will appear to be more desirable or interesting to you and other people and guys. Clearly this hasn’t worked, but I think desperation is the basis for all of this. You are probably more popular with other girls and you have had boyfriends, while she maybe has not. When you are in school, being popular (or even just being liked) is extremely important. Your friend is probably just trying to “have what everybody else seems to have” but not going about it in the right way.

If you talk to her and choose to walk away from the friendship, be as kind and gentle as you can.

I did fail to mention option #2 if you choose to not speak up, change the situation or leave.

That would be…. stay engaged but stop complaining about the person.

If you choose to hang on then you must cease to complain. Period.

Doesn’t sound like much of a friend to me. Why would you have someone like this as a “best friend”? Cut her loose.

I’m glad I don’t have a sister like that!

She’s severely disturbed and needs serious counseling. Not by you. That is “why she is so stupid”, to answer your question.

To answer your other question of how to “get her to realize that she doesn’t have to try so damn hard to impress me and that I’m not impressed”, tell her so, consistently, and also tell her she has been a huge liar and you know it. If she denies it, keep reducing your level of detail until you are saying irrefutable things about your own actual experience.

Also ask yourself why you are interested in spending time with this person, who acts this way. What “juice” do you get out of it?

I enjoy hanging out with her because we have so much in common and like I said, she is like a sister to me.

Also I have brought it up that I think a lot of her stories don’t add up and I know she’s lying but usually she just doesn’t say anything.

I agree with the majority of you saying she probably needs counseling but she just thinks she’s too good for any help with anything.

Thank you all for your help! Hopefully soon I’ll get through to her or she can learn to help herself! :)

I had a friend like this once, but we were not as close as you seem to be with your friend. One day I told him that he doesn’t need to lie to make his life sound more interesting – I like him just the way he is and prefer hanging out with him when I know he’s being honest with me.

In order to stay friends with her, consider this: treat her lies as the stories they are, only in a mild manner. You may find them amusing and be able to set them aside. The lying is not something you can change and pointing it out to her doesn’t work, You’re not in a position to give her the therapy she needs. Her friendship with you may be the only positive relationship she has. Continue to do the things you have in common as long as you enjoy that. If the lies continue to bother you, you may have to limit the time you spend with her.

If you are “so much alike” I would be wary that people who know her might think that you, too, are a pathological liar. Sometimes you have to walk away from things you don’t want sticking to you.

Oh yes, that is true, I would hate to be considered a liar just because my friend is one.