Don't be freaking out- this is not ur grade 8 physics class. What I'm about to share is more along the lines of the energy between people. Just like how the wind blows, the windmill turns, n the energy re-used, it's kinda the same theory with people. Have u ever noticed that when ur happy, u tend to crave for a particular someone's presence, n the same for when ur sad? The choice that u unconsciously make is actually based on how the connection is between u n this person. Take, for example, when ur heading for a party night out, u know just who to bring along because u know they'll add to the atmosphere n pump up the party. Vice versa, u know exactly who not to invite because they're not fitting for such an evironment n may probably bring down the fun-erometer. But that person who u wouldn't invite to a party may be the best chat-over-tea-time friend of urs.
Side note: that means, u shouldn't feel too upset about not being invited to an event, because ur friends know better than to put u out of ur element- so what if ur a bubble tea friend? I quite enjoy that too! (Considering if everyone thinks of bubble tea once a day, they will, by association, think of u once a day!)
On the back page of the same note, there are people who just walk around with bad vibes (by "walking around", i don't mean that literally, but more like the way the negative energy treads within everything they do). Maybe an example will make this a little easier to understand. I have a friend who I've known for years- since elementary school actually. U could say we used to be very close friends, but u know how the world changes u during the whole process of "growing up", so now we're not so close. Yet, we still maintain that "friends" status for the sake of old times. Except, after all these years, he's turn into a sarcastically negative ball of energy. I'm quite glad that we don't meet as often because, honestly, that'll make me want to de-friend him. Permanently. If ur asking why, it's because nothing that he says has any positive value n it puts me in a shyttie mood. So, why would anyone want to be around someone like that? They wouldn't. Like I said, I'm glad I don't see him much, or else u can kiss this friendship goodbye.
So what am I trying to say here? Stay away from negative people! It's like an invisible virus that they carry around with them. Once hit, u'll be all sour n grumpy- then YOU will be the one everyone wants to avoid. Just to be clear, I'm not saying u should run from ur friends who are having a hard time n need someone to lend a ear to them, but understand this friend before stepping in. Is she a person who's always pessimistic, or is this just a hiccup? If it's a likely scenario that u can make a positive change- aka. she's not hopelessly giving into the agents of the dark energy- then by all means go be a friend. If not, just take it that ur not the best person to deal with ur friend. It happens- no one is capable of managing all their friends' issues without going into mental breakdowns themselves. But u can be for some. In a way, if ur positive enough, talking to a "down" friend, u can take away a little of their negativity without getting affected. That would be the perfect solution. (Now run along n find urself positron friends! U can never have enough of those stashed for ur mid-life crisis!)
(don't make me do it!!)
It's in ur power to decide who u want in ur life- don't keep those that shouldn't be.